It depends on the client and the procedure / facial but...
Medical facial - I use acetone but VERY rarely. 99% of the time it is a pH balanced alcohol / H2O mix at 30% / 70%. Acetone is just too much for the skin and too much alcohol smells on the stronger side.
I use 2 cleansers by Sanitas lactic cleanser and enzymatic lactic cleanser. The second one gives a tingling like the peel pretreat. It really cranks up a good peel.