Cleaning tip of the day: So I've had my prechambers and retainer rings in the ultrasonic to decarbonize and clean them up. I initially used water, Simple Green, and a dash of Ballistol which does a pretty good job for most things and the main component, the Simple Green is cheap and easy to find. Even with the water nasty black there was still a lot of carbon in the PC's. I dumped, rinsed and refilled but this time used Marine Clean mixed 5 parts H₂O to 1 part Marine Clean. Hit start on the machine and instantly black clouds of carbon filth poured out of the PC's! Within a few minutes the water was pitch black again! I forgot how good this stuff was. I'll be using this on my horrendouslly dirty cylinder head next!
So if you all need a seriously good cleaner/degreaser --->
POR-15 Cleaner Degreaser
It is non-petroleum, water-based & biodegradable too. They recommend using on aluminum and a couple other things for short periods only but it works fast so it can be rinsed off pretty quick. No actual true endorsements from me, just good praise!