The best way to degrease bearings is like Pops said. Blast them out with motor spray and relube them with the bearing oil of your choice. I thought the superbrain 959 went higher than that....but i would not recommend the Intellipeak to you however. The Pulse charging it has over time isn't good for NiMH cells. If you can go for the Reedy AC/DC Quasar Pro charger. Yes, it is like $170, but you get a great charger with lots of features like cycling with discharging up to 20 amps, and charge rate to 6.5 amps, and linear charging
. The extra $50 to get the Quasar Pro is well worth it over the intellipeak (plus the intellipeak's power supply is REALLY noisy).
And no, by the way, using denatured alcohol wouldn't be good for a motor (i don't think?). Spray it out with motor spray as well. When you're done, make sure to relube the bushings/bearings with the oil of your choice.