I had an ocel that both surfed a PH and hosted it. It was one with a flat top, and he'd just settle down there and watch the world go by.
My saddleback also tries to host a rubber carpet anenome, and my female ocel is checking out the fake BTA as we speak.
I just want to say that putting a 12 gallon nanocube in our office was a fantastic idea. I have a mated pair of ocel in there, and every day they're doing something different.