Degreaser - Water based "Diggers" from Bunnings. Don't be fooled - this stuff is HARSH. You mix it with water.
Just wondering what proportion you would use with water? And how long to leave the parts in it for?
I think it is one part degreaser to ten parts of water. I usually leave the parts in for 10 minutes, and then monitor - sometimes it can take 1-2 hours.