I have tried it, and would not use it on crankcase parts because it might impair the fit of the cylinder. On mufflers however , the acid etch removes the ugly off-black, and restores the base aluminum coulor. The finished product has a very fine grained sandblasted-like appearance.

The crock method is the other remaining alternative, apart from mechanical cleaning.

A lifetime of model flight should make me able to dig up more solutions, but so far they stayed out of my field of vision.