yngldy mentioned a curry comb, and that reminded me of something I use to clean my horses' feet before trimming them -- brass bristle brushes. I've got two, one fine and one coarse, the bristles about half an inch wide by three inches long. The bristles are relatively fine and closely spaced. They are similar to the type of brush you can get to clean your grill, though those brushes are fairly wide and flat. The bristles have a little give to them, so they shouldn't destroy the velcro. I'll try to remember tomorrow to try them on my sneaker velcro to see if they work as well as I think they will. You can get them in places like Tractor Supply or Home Depot, and probably in some Walmarts or any hardware store. I think they are used for cleaning pipes for welding or soldering.