You can buy different grades of coco-husk. Are you using coco-husk fiber?
The grades are S, SS, and SSS. (S being larger pieces and SSS being finer chips), There is also 10C which is almost nothing but fibers and small chips. I have always bought the big chips (S) and I have never had a problem with it sticking. Thats actually one of the reasons why I use Cocohusk over aspen.
here's a link that shows the different grades.
http://riococo.com/index.php?option=...=115&Itemid=59