Originally Posted by Andy M.
Yes, but they are not very porous and they are only in the liquid for a few minutes.
You don't have to be boiling it the entire time.
I remember when I was a kid and we used to dye easter eggs with one of those Pas kits (you know, those little tablets that dissolve in vinegar). It wasn't uncommon for the egg underneath the shell to become dyed a little bit, suggesting that liquids can get through.
As for the OP, just give it a try and see what happens.