I use "parts cleaning solvent" (kerosene I think). There's two places in town that sell it. It doesn't touch dirt but eats anything oil based. It's pretty high dollar stuff too. I'm not sure if you should run it through your home made setup though. It'd probably eat your pump up.

Save a life, adopt a senior shelter pet.
The three main causes of blindness: Cataracts, Politics, Religion.
Name your dog Naked so you can walk Naked in the park.