I think he has gave in! It started about a week ago and the clowns have started cleaning a shell by the BTA and then started getting into the duster. I thought it was unhappy with the duster being so close to the shell.
I moved the duster to the other side of the tank and after a day she started again. The duster was pulling in everytime but now it seems to of give up and let's her take naps lol