Down to the dirty business. First spray all the dirt off. It gets in the way of the degreasers. Now that you have exposed all the chain lube style grease the degreasing chemicals can get to it. I have a floor stripper that works VERY well on oil based grime BUT this grease is special. It also has brake dust in it which makes it very stubborn. The best thing for brake dust also happens to work "ok" on grease and some oil as well.
Acid to the rescue!
I prefer Eagle 1 brand wheel cleaners as they have a relatively high amount of acid in them. These great bottles also are very resistant to the acid. Regular spray bottle pumps will fail within a few days under the acid chemical unless you rinse them after using. Eagle 1 sells the
Magnesium Etching Cleaner as well as
Chrome and Wire Wheel Cleaner. The Mag cleaner is very aggressive and the chrome and wire cleaner is a little less so. How can I tell? Well, when I apply the acid to my fingernails I feel much more comfortable with the Chrome and Wire Wheel cleaner. The amount of Acid in the Mag Etching Cleaner will definitely let you know if you have weak skin.
So just keep the water flowing at a trickle and keep it on hand. I just spray the acid lightly and then go to work with the toothbrush. The acid goes a long way so you don't need to use so much. Just brush it all over and it will start removing grease and oil within 10 seconds. The brake dust and grease will come off so fast that you won't be able to see what is getting clean and what is still dirty... then just rinse with the water and repeat till your done. It works great! If you get it on your skin or in your eyes just splash some water on it and it will dilute super fast. I don't even use gloves because the water will neutralize the acid upon contact. You will be done quickly. Once you have it clean just put the wheel up on a workbench and use a towel to get any residue off.