I scrubbed a set of green '68 Charger seats with trisodium phosphate, water, and a Scotchbrite. Emulsifies all oils and silicone, and most importantly, washes it all away. The acetone or lacquer thinner method just dilutes the contaminates as you wipe the surface. An autobody supply shop mixed up a quart of SEM to match the white rear seat I had, and it turned out great. No bleed through of the green, even in the pleats of the '68 seats, and it didn't peel or wear, but I sold the car in a couple years.