It will remove the anti-reflective coating on eyeglasses.
I use one a lot. Use water base and Hornady solution (or something similar) with good results. For guns I don't wanna tear down to make sure all water is removed and not rusting something, I use a solvent based cleaning lube (lucas, Hoppes, etc)
It will not remove stuff that is really caked on - or at least it will not remove it very fast.
I still follow up with compressed air and/or spray cleaner to get stuff that may have settled inside the parts.
Not the end-all of cleaning, just another tool.