I swear this WORKS so please try it!!
If you notice their fur is getting a static charge, SPIT in your hand and rub it on their fur. You only need a LITTLE bit of spit, so don't go crazy!!
Of course water works if you have access. It sounds gross but your cats won't care.
Every time I suggest this to someone they want to know why it works!! I don't know why it works, but I know it does work 100% of the time with my 2 cats.