Quote Originally Posted by crouton976 View Post
I could definitely see the aquarium gravel helping, especially after using one of Richard's bowls. My only question is what effect it would have on the bristles of your brush. If the gravel has sharp edges, I would think that you would slowly be destroying the bristles in your knot.

Smooth edged gravel, on the other hand, would probably work really well and keep your brush happy, too.
The gravel I used was smooth cornered, looked like it was sent through a tumbler before they sold it. I do think your brush would be damaged from sharp cornered gravel.