I use the coconut husk for my humidity loving reptiles with great results. I honeslty cannot say I've had a problem with it before.
Here's a tip though - buy it at a greenhouse. It will look the same (be in a 'brick) but be under a different name. Usually it costs 1/2 to 1/3 the price than if you bought it in a pet store.
I am highly prized for my meat. :eb: