I keep small glass food jars around so that I can fill with cleaning solutions, recap, and save for use again. I also use coffee filters to clean fluid some before reusing it. I like using brake cleaning fluid, I just spray into small jar, 4 oz or so size, and place bearings in it and shake around. I will use another jar to clean a second time to be sure all grease, dirt, residue is removed. You can also use laquer cleaner, even automotive engine cleaner. After cleaning bearings then blow out with compressed air or allow to dry on paper towels. Be sure to remove shields to insure that all dirt is cleaned out.
I just bought an ultrasonic cleaner at Habor Freight on sale for $25. I also bought some liquid ultrasonic cleaner from jewelry department at Wal-Mart to use in ultrasonic machine.
After cleaning bearings, I re-oil with Mobil 1, or I use grease, depending on the application, whether its for on-road or off-road. I prefer grease in off-road bearings because it will help seal the bearing to prevent dirt from entering. Oil is preferred in on-road bearings to reduce rolling resistence as much as possible.