I've used toe warmers and they are helpful. I read somewhere here that hand warmers are half the price and a little larger so I bought some with the intention of using them for my toes. At the check-out I mentioned this and the sales clerk said that the hand warmers do not have the adhesive backing. I'm thinking I can still use these sandwiched between my inner and outer sock and that they would slide around too much - or that I could just apply a little strategic tape.

Anyone with experience using a hand warmer for the toes?

^^^
I use hand warmers for the toes. Either above or below the toes and occasionally both if it's cold enough. Generally I don't pull em out until the mid teens or so. btw for those who may not know. If you put them in a sealed baggie after use, you can use them again.

I used some hand warmer last week, sandwiched between my socks and just above my toes. Hand warmers may require a little more space in your shoes/sandals.

Yes, hand warmers shoved up into the toe of your boot will work....

BUT

The success of these chemical warmers depends on whether or not they can get sufficient air to work properly.

A number of years ago, I had used a gore tex sock, with the hand warmer inside of it. Never did work right. Removed the sock and feet were toasty warm. So now I wear the warmer outside of the gore tex sock. Sure I run the risk of getting the warmer wet, but at least my feet are dry.

The chemical warmers marketed for the feet may be designed to handle less air flow, as would be found inside of a boot and perhaps would work better. But the hand warmers I purchase seem to work fine.

In short, try to get more air space down there. If you wear 2 or more pairs of socks put the warmer inside the outter sock.

As to your original question I never did have an issue with the lack of adhesive and the hand warmer stayed in place ok.

I will put hand warmers on top of my toes in my insulated waterproof steel toed workboots
when the temp gets down to about negative 20F. I've never had a problem with them not
getting enough oxygen to heat up or staying put without adhesive.