Exactly! I made a holder for my mag cleaner that attaches to a drill. Makes cleaning/buffing quick and easy. (See video in post #3 of this thread, https://www.reef2reef.com/threads/long-time-acrylic-owners-cleaning-tips-wanted.793176/ .) As a rectangle, it tends to "walk" when the axis is not perpendicular to the glass. A circular footprint would be much more stable and produce less turbulence. I was thinking something along these lines, (red and blue are north and south poles of the magnets.)This is interesting- for wet use with a Dobie pad or similar? To pull off tough coralline?