I like to use Brake Cleaner due to the fact it evaporates and leaves no residue. Don't spray it on the bearings though.
Router has listed a cheap way that works great.
Bj has listed an excellent product,
I also use the DuPont Teflon lub I got from ACE hardware it also works well, it cleans and lubs the bit all in one shot...puts on a thin coat of Teflon on the cutters , slick stuff
Locktite DuPont Krytox PTFE High Performance Lubricant http://www.sandsmachine.com/grease_t.htm
There's many ways to clean your bits.
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