since atf is really just oil, seems like it wouldnt help much, but actually add to the problem. it will coat everything, burn only partially, and contribute to fouling/build up.

i have lightly drizzled water into the carb, and it is vaporized into steam, and over time/repeated use, will remove deposits. dont add to much at once (never a garden hose blasted into the carb) unless you wish to witness the effects of hydro-locking. water wont compress, but your rods will. use it sparingly, and keep the revs up, and water will clean out a lot of crap.