I got by with a Park double tool with a wrap or three of Teflon tape for a while but the right tool is good to have.
I bought it half because I just wanted to support a toolmaker like Jim Stein.
And buying tools is in the rules....

More detail required. I wouldn't advise wedging these tools in behind the crank with force in order to remove the crank. Doing it that way will result in the bottom bracket bearings taking the reaction force needed to separate the crank from the spindle. You don't want that.

I have a few of those Jacobs wedges, for my chucks, etc, but I'd not use them for this application personally. I'd be afraid to mar the back of the arms. But if I didn't have the right tool I'd be tempted to try them, maybe taping the arms first.

One trick that you can use to lessen the needed pulling force, potentially allowing the use of a Park double-ended 23mm puller (what I used for years), is to apply a modest torque to the puller and then stand on the pedals and bounce a bit, then turn the cranks a half-turn and bounce again.
This goes a long way to helping the crankarm off of the squirming square spindle end.
Repeat as needed, re-torquing the puller each time.
This has always allowed me to remove heavily-tightened and stuck crankarms without breaking another Park tool handle and without stripping a single of the many Stronglight arms I've pulled.

No, the force is confined between the crank arm and the face of the bottom bracket cup. The bearings aren't loaded at all in the process.

Wait, think that over, the arm will pull fiercely on the spindle and thus brngs, no?

There they are - Thanks John - These wedges have multiple uses all around the shop...

apg - Don't forget to torque them down at re-installation - Go to about 28-34 Nm (250-300 Lb.in.)...

I have always respected how the guys on this forum try to hold back on purchase of specialised tools that will seldom be used...

And yes I have to admit I have used a tierod wedge successfully (but I don't recommend it)...

Sorry, I've looked over the FAQs, but I don't remember seeing anything in the rules about buying tools. Can someone link to it so I can make sure there's nothing else I'm overlooking?

To be honest, I'm really not just trying to be cheap, and I don't mind supporting people who make good tools and parts. And no offense to Jim Stein, but when a particular tool or part appears to be the only game in town, and it's priced significantly higher than similar non-compatible tools, it makes me question whether the part or tool is maybe being priced up a bit more than necessary.

Well, could be Echo victor but, knowing what it takes to makes things on a metal lathe, I myself don't think what Jim Stein charges for these is excessive.
If I thought I could make them for less on my lathe I might give him a run for his money but, no way. Also, I'm personally glad he has made them. Where else was I going to find one? ...is how I looked at it. My Park CCP-1 with Teflon tape worked, but I figured it was perhaps only a matter of time before I screwed up a nice crank set.
BTW, there are no tool buying rules. To each his own on that one.

It doesn't hurt the bearings on drill presses or lathes when you use the wedges to remove the chuck, so I doubt it would hurt your bottom bracket bearings.

I myself would be surprised to see any bearing damage from that method, but some bottom brackets have quite better/worse durability than others, and some crankarms are stuck so tight as to invite tool breakage.

FWIW, I've seen some bb bearings survive heavy hammering of a cotter pin with no visible or apparent damage.

Be that as it may, it is not an intended or approved function of the BB bearings to resist unspecified stationary/impact loads. Just sayin.

My take. Bearings in drill presses are designed to take axial loads. Side note: That is one reason I never use a sanding drum, or whatever, on my drill press, which presents radial loads on the bearings. I've heard you can destroy the accuracy of a drill press by forcing radial loads on it. Not sure if it's true but I never wanted to find out.
But to the point. I actually typed out and nearly posted something similar to this;
"the force is confined between the crank arm and the face of the bottom bracket cup. The bearings aren't loaded at all in the process." ...but then I thought about it and deleted my post.

During the operation of pounding the wedges together the bearings will be loaded against the fixed and adjustable cup races, with some force, as the wedges are pounding against the crank arm, which is pulling against the bearing shoulder on the spindle, which is pulling against the balls, which will be then pressing against the cup races. And not just pressing, but hitting the cup race with impact every time the wedges are hit.

But that's not why I don't do it. I went down and tried my Jacobs wedges on my spindle when I first read about this technique. I only have size 2 and 3 wedges. Size 3 fits around the spindle about right. But I looked at that steel wedge up against the nicely turned, tapered shoulder on the back side of my (soft aluminum) crank arms and decided, "no way". This is sure to mar the crank arms, I thought. This is only for Record arms. I didn't try the wedges on the only other crank set I have, a Stronglight. Anyway, I decided it was too dangerous, for me, and bought the Jim Stein tool.

I'm not stating categorically that using wedges or a similar method to pry the crank loose from the BB will damage the ball bearings and/or races, only that they weren't designed or intended for the function of resisting significant stationary impact loads. Axial loads while rotating, yes, of course, drill presses included.
When you use a product in a way for which it was not designed or intended, you take your own risk of damaging it. You all know that. I'm just pointing out what I believe bottom brackets were not designed for.
My understanding of the Jacobs chuck wedges is that the preferred method is to use a C-clamp to squeeze them together around the drill shaft (rather than hammering). That's probably good advice if you're going to use them to remove a crankarm also. Assuming you have a C-clamp that's stout enough. If your C-clamp can't take it, maybe it's time to consider using the proper puller instead. An appropriately sized two- or three-jaw puller might work for the NDS, but that's probably a tough one for the drive side.

For removal, Sheldon suggests using a gear puller as a viable option. I've not tried it myself, but if the need arises to remove my stronglight cranks I'll be visiting the local auto parts store to borrow one.

I'm in the same boat. My Raleigh GS was well cared for by the previous owner so I don't foresee a need to pull the cranks anytime soon. When/if you do pull your cranks, please post about it.

TIP: Keep your eyes out for Park Tool CCP-1 or some versions of CCP-2 which have two threaded sections. For example: Missed Opportunity. The "nut" which threads into the crank arm is double-side with threads for either standard or Stronglight/TA cranks.

That's a bad link. Rather than correcting it, here are some better (cheaper) missed opportunities:

https://www.ebay.com/itm/111048347409
https://www.ebay.com/itm/200881881985

^Indeed, link corrected. Thanks. You got the idea.

Almost sold mine to a member here ... but some folks just can't help but look a near gift horse in the mouth. So, I kept it.

We're going around the block again. Early Stronglight is NOT the same as TA, see post #14.

Indeed. Sutherland's explicitly warns against using the Park tool on pre-1982 Stronglight cranks: