Xmas tree rock safe with mantis?

[joetbs]

I have a N. Wennarae, about 2". I have him in a 5.5g with a bunch of softies, some lps, lr, ls etc. I was considering getting a Xmas Tree Worm Rock(Spirobranchus sp.) Would the mantis harm this? Would feather dusters/cluster dusters be safe as well?

thanks.
joe