Excuse my ignorance but I want to be sure I understand it correctly. Do you mean doing something similar to this?Put the anemone on inside and put a concave piece of rock across its body and foot. It most likely will attach to the rock and then dig down to the sand.
I have a lot of success for sand dwelling anemone with this method.
It really needs some leverage to dig into the sand and it will be much easier for the anemone to use the rock as leverage to dig.