I do most CG stuff with the fingers as well.

However, if you want an easy "machine" it's very simple. I have a bit of scrap wood that I drilled a few holes in. I put a wood dowl in the hole, and one of those penncil eraser caps on the top of the dowel. For heavy planes, I clamp the board to the work bench first. The only problem with this approach is that very heavy planes might damage themselves by sitting on the eraser ends, too much weight on such a small area, but I've used it on planes up to 14lbs with out issue.