This works a treat, willeven remove powder coating without too much grief, it's cheap, quick delivery, I wouldn't use anything else these days.....but beware, it's pretty nasty, you need good ventilation and some decent gloves
These days I mainly use Bio Strip 20 paint stripper. It is reasonably inexpensive and does the job. I've done a few bicycle frames, and a lot vintage farm machinery with it. It is water based, easy to handle, easy to use, and rinses off well. odd bits here and there need 2 and sometimes 3 coats of it, but that is usual where there has been paint build in corners or multiple layers.
I have even used it to strip 3 month old agricultural enamel paint out of a blocked up solid paint spray gun.