Crystal Light stains

I used to drink one or two soda's a day. Ginger-ale and Coke, mainly. Now I've got to cut out the sugary drinks, of course. Since I get tired of drinking plain water, I started to use diet powdered drink mix and a two-quart pitcher now regularly occupies the fridge. Every day I mix a new batch. I've got to figure how to keep the powder off my fingers because the damn stuff never comes off!