You are right, the title asks one question and the post itself asks another.

As to the combustion chamber cleaner, I have used several different brands. Most of them look, act, and even smell the same. Kinda white, foamy, slick feeling and water soluable.

I use it to clean carbs and fuel related items mostly. Works great and doesn't hurt the coating on aluminum. Usually the spray from OMC and the pour can from GM are the easiest to find. But it is a lot more expensive than regular carb cleaner.

Combustion Chamber Cleaner was the ONLY product OMC (Evinrude/Johnson) recommended to clean carbs and related components.