If you look up glazing compound,
(Google- Glazing Compound) you will find that it is very much like plumbers putty. The purpose is to primarily prevent water and air intrusion, however it also provides a minimal thermal break and absorbs minimal shocks as well.
Putty tape, plumbers putty, glazing compound are basically the same thing with the same purpose.
The main thing is to NOT use any type of adhesive. If you do and have to replace the glass in the future...well you will see why real quick that you do not want to use adhesives! You will cut your hands trying to unstick the glass shards from the frame. And that must be done completely or you will not have a good seal...
In truth, the fellow that told you plumbers putty probably didn't know or remember 'glazing compound' as that is the actual name for the product.
I hope that helps. Good luck!
