parrisw
Tree Freak
Looks like I'm going to have to make a few phone calls...
My old kart engine builder from over twenty years ago used a solution he bought in a 20 litre (5 gallon) drum that he just dropped aluminium cylinders and heads into and they emerged immaculately clean, looking pristine and new.
We never had to touch one with a brush, it was magic stuff (and probably banned these days.... )
Sounds like the old carb cleaner we used to use. It comes in a bucket 20L, and has a basket you soak the carb in. Worked wonders on pistons, I used it all the time for pistons. But you can't get it anymore around here. Was brutal stuff though, even if I could buy it, I wouldn't use it anymore.