I don't have a clip chart this year, but I did put student numbers on clothespins for lunch choice. I teach 3rd and the kids had no trouble remembering their number even on the 2nd day of school! I do line them up in number order and they have to write it on every paper, but I think it is something they can easily remember. I also use their student numbers on their mail boxes and cubbies.
I think your idea will work well.