You can build a vibrating cleaner (like the expensive ones used for reloading) for just a few dollars.
Find a used shop, goodwill etc. and pickup an old vibrating foot massager or other type of vibrating massager.
Mount that firmly to the bottom of a board. On top, affix a tupperware bowl that has a lid. On another same size square of plywood, drill 4 holes in the corner to fit 3/6" all thread(any size actually will do). In the board with the vibrator drill 4 corresponding holes LARGER than the all thread. Place springs on the all thread and drop the vibrating board on top of the springs so it is "floating" on the springs. Put your cleaning media(crushed walnuts, etc.) in the bowl, add the coins and turn it on.
I built one for around $5. It works great to clean brass for reloading.