I have found these which I thought might hang quite nicely from the floor plugs:
Naturals treats:
Boredom Breaker Naturals Treats Dandelion Sticks | Net Pet Shop
Hanging Gnaw Stones:
Boredom Breaker Naturals Gnaw Stone Stack | Net Pet Shop
Thank you all ideas are much appreciated by me and Jaffa! So many of us have Imac Fantasys that its good to share ideas!