I never used the hot glue dots, but I do use adhesive backed sandpaper. Works very well to keep rulers from slipping.
Now, for my "duh" moment...I wear glasses and have prescription sunglasses. For the life of me, I couldn't find them and figured I'd lost them at a store or somewhere between shopping and home. I couldn't afford to replace them and started saving for a new pair. About 3 weeks later, I went into my vegetable cold storage for a bag of potatoes. Lo and behold, I'd put my glasses in a brown paper bag that was filled with potatoes. How? When? This is another one of those "great mysteries" of the world.....LOL