Seafoam.

1/3 in the fuel tank, 1/3 in the oil, 1/3 in the intake manifold through a vacuum line, usually the brake booster. Then have fun and floor it everywhere and see if you can see anything in your rear view mirror other than white smoke. Do that until most of the smoke is gone. Then let your car sit for like an hour or 2 and change your oil.

That's what I do.