If its that dire, id go for a kill or cure'm method. I would wait it out though and see what others might say....
Freshwater dip for 3-5 minutes. The hard part is adjusting PH to get it close, and keeping the water near the same temp as the tank its in.
It worked for some fire gobys, i dont know if it will work for anthias. If the fish lives, you will see little 'exploded' ich cysts on the body of the fish...its kind of rewarding.