I don't drink and won't keep Everclear in the house, so I use 91 or 99 percent isopropyl alcohol (not 70% -- you want the least amount of water so 99% or the high proof potable stuff, and not denatured alcohol) -- a small amount on bristle pipe cleaners or a brush to clean shanks and stems, followed by dry pipe cleaners, repeating until the two come out relatively clean -- I never want the shank really to be wet or remain wet -- then I use compressed air to blow dry the shank and stem, then let the pipe air out for a day or two before smoking. Never had an issue with taste and certainly not with any toxicity. I wouldn't dump the alcohol in the pipe. But used in small quantities on a swab, and dried immediately (the alcohol evaporates very quickly, esp. the 99% stuff), it's fine. I don't do it with every smoke....maybe every 5 or 10...and I'm careful not to get any alcohol on the finished exterior of the pipe.