The $7 tube with a hole in it? that's in your garage where you keep your Dremel? go ahead and practice

I don't know if it's still available because it had warnings printed all over it, but the glue brands used to sell accelerator that you sprayed on. (edit - yep and the bottle even looks the same as it did 35 years ago)

I've used the benchmark Rema glue and patches as well as Park, Slime, and totally generic bulk stuff from EBay. They all have worked equally well given proper prep and the location on the tube. Some locations, like near the stem, or sometimes the raised seam on some tubes, are just hard to patch. But given a clean, roughed surface and proper applicaiton of the patch, They all work fine. My latest strategy is to buy a whole bunch of tiny (like the size in Rema patch kits) genaric patch glue tubes from EBay because they tend to dry out before they're used up. They aren't exactly one use tubes, but I don't mind if they turn out to be.

I will note that Slime sells a larger jar of fluid that is labeled as "rubber cement" but has an ingredients list matching vulcanizing fluid. The smell is also consistent with that of vulcanizing fluid. I've used it with Rema patches with results identical to the Rema fluid so far. Note that the only reason I bought the Slime brand was because a friend was selling a bunch of cans at the bike swap and I just couldn't turn down the price.

Here in hot Arizona, an opened 3g, 5g, or 7g tube of fluid will usually dry up in 6-12 months if left untouched in a covered place such as a patch kit box, even with the cap screwed on tight. Unopened sealed tubes also have a history of drying up and becoming unusable in 4-7 years. You'd think this was unlikely given their sealed status, but apparently the lighter aromatic fractions can gradually pass through even "sealed" seams in the tube given enough time.

Puff, puff, pass, or huff the large bottle of cement until it makes sense.....

The Rema vulcanizing fluid lists N-ethylcyclohexylamine in addition to hexane and a heavy naphtha. Slime’s rubber cement lists only hydrocarbons. The N-ethylcyclohexylamine is a promoter for the vulcanizing process. I have an old post on the topic. The link to the Nocil article is dead but I found a copy of it if you want more details.

I gave up on roadside glue-type patches years ago. I keep a spare tube and Park stick-on patches in my saddle bag. It's a couple years since I needed to use any of the instant patches. I USED TO patch tubes and reuse them, but then one failed after a couple months. It was on a wheel-on trainer, not the road, fortunately. But that put me off of patching tubes for reuse, because it could have happened while I was descending at > 30 mph.

I use this glue

​​​​​​https://www.autozone.com/suspension-...store_set=true

I've used the slime large bottle and the tiny rema patches for years, never had an issue. I've also used other folks "rubber cement" in a pinch, same thing. As others have mentioned, prep, and proper technique is what it's about.