Protect tile grout from wood stain when staining fireplace surround
I'm thinking removable caulk might work.  I've used it to seal windows during the winter, and it comes off pretty easy from glass and plastic, so it might work.

This would give you something a little larger to work with, as far as making sure it hits all the right spots, as well as when trying to remove it later.  Leaving a large bead would also make it easier to adhere tape to.

IDK if tape sticks to it, but it's an idea.  I also don't know how well it would come off  grout, or if it would damage it when trying to peel it off.