chris_barry

I've used the shaving cream on half a dozen engines and I'm pretty sure it pushes all the swarf out. I got the trick from a thread repair specialist who makes a living removing broken bolts and repairing threads. I position the piston near BTC on the firing stroke and use some tubing to fill the cylinder from the bottom so there are no air voids in the shaving cream. When you turn the motor over any swarf is concentrated in the first few inches of cream. An awful lot more comes out after this.

I also give a generous squirt of CRC when I've finished run the engine for a few seconds with the plug out/injector disconnected to blow out any residue.

You are right that the overheated plug has probably dropped stuff into the cylinders already. I would get a timesert fitted and then see how the engine goes.