[charlie fitton]

I used a water/ molasses mix in the ratio of 10/1, so there is a wide range of options here.

Photo's from a v8 timing fixture attached:

Before, during, and after..note that the brass was not destroyed, and the decal parts are still in place. Took about 10 days on the kitchen counter..

Toothbrush , soap and water to clean up. A pressure washer for bigger bits, I imagine.