I use one on many of my firearms. It does an amazing job in general. On some things, like M1 rifle and carbine bolts, you can clean things out without disassembling the assembly and they come out far cleaner than you could do without complete disassembly. Caution: never use Simple Green if there are any aluminum parts involved. I have seen the combination of temperature, chemicals and ultrasonic cleaning basically strip the anodizing and damage the aluminum. The short version is that I find it incredibly useful for cleaning all kinds of things, but a little care is needed.
