How should I clean my piston heads while still in the car?

[BMW-F1-FAN]

The head is at the shop being reconditioned.

[632 Regal]

Laquer thinner, toothbrush, rags and tape around the sides of the pistons so junk and fluid dont get into the rings.

No power wire brushes on this job.

[Anton CH.]

link (http://www.bimmernut.com/wwwboard/e34/messages/90125.html)

[Robbo]

No, No, No, you gotta get out the car and lift the hood ;-)