This is what is working for me to clean the outside of the case. These small brass wire brushes on 1/8" shank can be bought by the dozen on Ebay for a few bucks for a dozen. They can get in the tight corners of the recesses on the case, where the grease hides. Not perfect as it's pretty dusty, I wear a paint mask and should get my 3M for this, but I have these in my workshop.
Using denatured alcohol in a Milwaukee Sure Shot and using CLP for some stuff. I know that won't harm aluminum as the military uses it on AR receivers. It's a cleaner, lubricant and penetrant. Not my favorite odor, but beats Ballistrol which I have and have used...odor is brutal, IMO. Actually I have Frog Lube that is also used on ARs, and I think it has a cleaner.
Anyway, here's an example of how the top cover came out on the outside, I went over this a couple times and the small brass wire wheel gets into those small corners in the tabs and such, that's the hard area for me to get with a scotch brite.
