EL44 400 Grit Dremel Tool
Just one look at this brute tells you that it's not for kid's play, that this tool is not for you... Again, you'll have to trust me. :-) With the 400 Grit, this is a grinder!
But, this is the VERY BEST tool that you will ever find for knocking off cement-like encrustations, hard dirt, etc. It also works great for cleaning/smoothing "zapped"coins.
Beware, as it WILL HARM YOUR COIN'S PATINA! if you're not careful. This tool definately will take practise (like all my Dremel tools, I suggest you practise on crappy coins first), but you'll be amazed and very satisfied with your final result.
I use this tool as a real work-horse, and it hasn't failed me yet.