Had the same issue last week. For the nooks and crannies, I used a STIFF rotary wire brush; the type with the wires protruding straight out of the end parallel with the 1/4" mandrel. I put it in a cordless drill and you can force it into all the corners and nooks, etc. Took 10-15 minutes and worked great and didn't affect the appearance of the surface overall. The brush I used is worn down to about a 1/2" at the tip so it fit those areas pretty well.