Several years ago while working at a gas station a guy came in with his car smoking and limping along. Glen, the owner, told him that it needed a valve job and would cost a couple hundred bucks. The guy said something like, “OK, I don’t care, just fix it”.

The guy left and Glen, the station owner, parked it at the far corner of the station lot and poured in two cans of Berryman’s Chemtool into the oil and another can into the gas tank. He let that car sit out there idling for about three or four hours. It smoked like a burning tire for quite some time. He shut it off, changed the oil and filter and I took it for a test drive …. ran smooth as silk.
He then steam cleaned the engine, painted the heads and valve covers and charged the guy for the valve job.