Don't worry. I have no intention of using duct tape for anything ever. It is the most miserable tape. I have done all sorts of stuff with gaffer tape, however, and it is not that expensive. I think $30 worth of various sizes has lasted me almost three years, and I'm not about to run out any time soon. It has never got gummy or flappy on me.
These are holes starting to form on all the outside corners of a bellows that was described as "in like new condition". Still trying to decide whether it can be a quick and easy fix, or if I should complain to the seller. I want to keep the camera, so complaining would pretty much be pointless.
I will look into E-6000.