I did some testing with wooden dowels and Styrofoam coffee cups and the winner is LOCTITE Power Grab FOAMBOARD CONSTRUCTION ADHESIVE. This costs about $5.50 at Lowes for a
10.1 ounce tube designed for the small caulk guns. It has a resealable cap.
(1) The bond is much stronger than any other adhesive tested, gently pulling the 1/4 inch wooden towel glued to the top of the coffee cups at its best leverage angle always ripped the cup, the bond never broke.
(2) It was much lighter than any of the other glues, it has a consistency of foam itself, it is about as heavy as shaving foam.
(3) It is amazingly easy to work with, I only needed a single piece of 3/4 inch tape to clamp down the one spot most needing to be clamped, the glue itself holds the pieces firmly together. A wet paper dowel can easily remove every trace of excess.
(4) It seems to wash off with water, at least before it dries.