Puggle roll?

I am not sure if it is a puggle thing, or a general dog practice, but every time Puggles sees a door mat he throws himself down and rolls around on his back. The larger and dirtier the mat the better. He would do this all day if I let him. Unfortunately once he bends down, it is near impossible to stop him. I have resorted to pulling, dragging, threatening, and leaving him there. None of the above work very well. It is really embarrassing when we walk by a fancy restaurant and he rolls himself around in front of a ton of people. After realizing that "no" wasn't working, I am now using treats to lure him away from the mats, and when possible, avoiding them.