I use an old butter knife to stir glitter into the plastic. The glitter clumps to the plastic on knife blade. I then scrape and stir in the glitter a little at a time.
Another option would be to mix the glitter with a little raw plastic.
Here is an example of the RTV silicone that is being referred to: You can get it at Hobby Lobby. The cost of RTV "mold making silicone" is what has driven many to use regular silicone sealant (like you use to seal around your tub).
Those look cool.
I have been using deer hair to make tails and they look really nice and seem to be stiff enough to help the action. Similar to a Bull Shad tail.
Check out the Alumidust product. Watch Larry's video it is interesting. I have not tried it.
http://www.alumilite.com/ProdDetail.cfm?Category=Support%20Products&Name=Alumidust
I use floured salt. I heat the salt to 300 F in a pan on a hot plate then stir slowly into plastic. Moisture is gone and it will not cool your plastic. Works Great!!