Coco husk is fine for snakes. Some people tend to not like it because it seems to be "dirtier" than aspen or cypress. But it is perfectly safe and if you like it and Poprocks seems to like it, there's no reason why you shouldn't use it.
As another option, if you want to get away from a wood product altogether, is this: http://www.cageliners.net/ I use these in all my tubs and they are great. Shredded fern pulp is another good, safe choice: http://www.blackjungleterrariumsuppl...Qt_p_1999.html