This thread got me wondering about road tars and undercoatings in fender wells and similar places. From my experience none of the strippers have removed any and neither did reverse electrolysis.
I say that from experience, having tried both routes trying to get paint to stick inside my fenders, on the advice of the guy who manufactures the paint I use, I finally borrowed a 40# sand blaster and got the job done right. At least I haven't been able to blow the paint off with an air nozzle like I could before.
So while I have been resisting the whole 'Blasting' thing for years as a C.heap A.ss S.tovebolt O.wner I have finally been converted. (you still have to be careful about the media you use)
For small intricate parts I can see the usefulness of a liquid stripper, but I see them now more as 'specialty' tools when 'better' tools don't fit.