OK so I have talked about this before. By no means do I say this is the rule, maybe more of the exception.
But.... I have a porc who I have had now for prob like a year and a half. During his time with me he lived in a tank that had at one point: a long spined urchin, a choc chip starfish, 2 different anemones (a seabae and a BT), and many various snails and hermits. He never, and I mean never, showed any signs of aggresion towards any of these items. In fact the only thing he ever took a nip from is a maroon clown, that had a tell tale half circle piece missing from his fin.
Ironically during this time that he was in this tank I had a good size snowflake that was also in there. Again no problems, he left everything alone also.
With this hobby there are many more exceptions then there are rules in my opinion. I am fortunate that I have enough tanks that if I put something in that is not working I can move it to another tank.
, I also temporary had a really large sapo in this tank, that within 20 minutes was trying to eat my starfish and trying to figure out how to eat an anemone. So be careful, but with a small well fed porc I would say try it. They are truly I think one of the best fish in this hobby, and a joy to have. Mine has learned to eat from my hand, and spits water at me when he is hungry.