If you have a small air compressor at home, you may want to try a home-made "soda" blaster. Think air gun shooting out baking soda. I use this combo to clean carburetors in lawn and garden equipment. After blasting the carb, a soak in water dissolves the left over baking soda. The finish on the metal is very similar to bead blasting. YouTube has several videos on home made soda blasters.