Cleaning connector housings

Does anyone have any suggestions on what to use to clean dirty electrical connector housings? I have a number of connectors that are covered in grime. Water is a problem because of corrosion and other solvents might attack the seal material.

I'm not sure how to get them cleaned up.

Dude, I've got the best method for this. Borrow your mother in law's ultrasonic jewlery cleaner, tell her its because you want to clean your wifes rings for her. Fill it with boiling water and simple green, 50/50 mix, and put the connector housings in there for an hour or so.

I think I'll actually buy a cheap ultrasonic cleaner out of china for this, as it really did such an amazing job. The connectors in the attached picture are from my RX7 and they were completely filth when I chucked them in there. I did exactly zero prep work, just depinned them and chucked them in. They honestly look damn close to brand new now.

Wow, stellar!

That's perfect!