i personally like acetone, aka nail polish remover, in many situations it is actually a better solvent than even 99% alcohol. And i still do the salt trick with it. and it worked really well on my bong, it cleaned it in seconds. i actually just tonight just picked up more to do my other pipes in, and acetone is actually used as a glass cleaner in high precision scenarios, so i feel that the glass gets cleaner as well, it also evaporates easily and doesnt let the salt get dissolved to easily.

try it, and compare it.