Under shelf toothbrush holder

I don't like to make holes in the wall, and I don't like the suction cup thing either, I feel like it is going to fall down. I have a 21 cm x 1.65 cm shelf, that I was thinking to mount this support to. I added the initials of the toothbrush users, and tried to put some holes in it, not to use too much plastic to print this. This never materialized, as it was a little bit too complex. I made a simpler version with a suction cup