I've seen a product which I think is call The Eraser at some local home-improvement places. They look like 4"x4"x12" charcoal briquettes, are very abrasive, and are shown on the package to be good for stripping paint from wood. Just like a regular pencil eraser, the eraser wears down as it is used, but in this case leaves sand-like particles.

Has anyone used this product, and more importantly, do you think it would be useful for fairing a kayak? I was thinking they may be good for fairing the inside, but since the eraser's surface doesn't remain flat, I'd stay with the fairing board with coarse sandpaper for the outside.

Dean