Ever since I used a wheel cleaner that is acidic, I've begun to get corrosion on the outside of calipers, at least the toyota 4x4s up front. (I stopped using it, but unsurprisingly the rust remains.)

I figure this is a good excuse to paint them so picked up a caliper paint kit from the local part store. But I'm wondering what's the best way to remove the rust prior to painting? I am going to unbolt the calipers and remove the pads, but don't want to remove the brake lines if I can help it, so whatever I use has to be something that can be used with the car up on stands in the garage. (for example: rinsing with huge amounts of water won't be an option.)

What do the brake painting gurus suggest?

It looks like you can use a wire wheel or cup brush on a drill to hit that rust. I would try that from looking at the picture, then if theres any left you cant get to I'd spray it with an acid or at least a rust converter type stuff. Then prep and paint as per the caliper paint kit.

Spray it with degreaser and or brake cleaner. Then scuff it up with a scotch brite pad. Spray a 4-5 light coats of paint rather than fewer heavy coats