I use one of the flat plastic tools that people use to rub down decals, vinyl lettering, window tinting and fiberglass or bondo body work. It isn't sharp and it's a bit flexible. I actually use 3 or 4. I put them in the freezer for 10 minutes and then pull them out one at a time to use. The flat, cold edge usually gets the foot to start releasing. After that it's easy. I've had it work on some rock attachments too (but not all). The tool has a rounded corner and I use that against the foot as far down as I can get it. I've also used the rounded ice cubes from our ice maker in the refridgerator (we use RO water and filtered again at the ice maker). The rounded, pointy edgw of the cube can be worked against the bottom edge of the foot. It works, but the ice melts pretty quick in 78 degree water!