Glad my wife gets the "teachers discount".

Regarding removing adhesive residue, I use the black tape (don't know if it makes a difference or not) and pull it back on itself after sanding the primer down enough to show the tape again. Most of the adhesive normally comes off for me, but any extra is easy to remove by dragging a small plywood stick down the groove, then rubbing it with my finger. It just kinda rolls up in a ball and comes out. A wipedown with alcohol takes out the rest.

Maybe there is some better stuff out there or a better method?

Bob