As I said in another post, I scored a ton of cedar 1x1 off of Craigslist. Some of it has a grooved channel down the middle--I'm assuming it was meant to be decorative. The groove does have a "triangled part" in the middle, though it is flush with the surface--it doesn't stick out any. From what I've read the whole idea is to give them some sort of guide and where to start the comb--do you think these grooved bars will work? They are 1 1/2 X 1 1/2, so I'm thinking to rip them in half and then try to use them.....Whaddya think?

Pics below.....