Did alot of these back when I was still turning wrenches for a living. The solvent is a very mild additive that is used to soften any clutch residue that might be clinging to the filter. If it's like the stuff i was using, it won't harm anything unless you are already to far gone with tranny wear. The only problems we ever saw,was if the tranny was on it's way out, it might speed up the process. The flush itself uses a special machine that backflushes the filter, essentially cleaning all the crap out of the screens. They are not like a regular paper element filter, they are made up of a fine metal mesh and they only "screen" the oil and keep the debris in the pan, out of the trans internals, not "catch and hold" like most other filters do. This flush is the only way to get all of the fluid out of the tranny. Dropping the pan only changes 1/3 to 1/2 of the oil, leaving dirty oil to mix with the new, essentially making it all old again instantly! If done on a regular basis-before troubles start, this flush is a better way to go imo. The fluid is what does all the work in an automatic, it cools,creates pressure,and helps prevent wear. that's a big job for any fluid. I say don't knock it till you try it, it just might surprise you how much crap comes out of the tranny this way!
