I have never tried it, but I have heard that it works. I am going to do this next time I find it really cheap and on sale. I am addicted tothat stuff, I cant drink coffee without it. It would also be idea great for their seasonal flavors.
I have and it works great. I put it in baggies so I can thaw small amounts at a time. Once you defrost you shouldn't refreeze. I have learned to double bag as some seals look and feel closed, but there may be a gap/tear/hole you can't see.