Either the powder or (gelatin) capsules with no water
This is my experience, after I was thinking about the same issue. I never took creatine during a dry fast. However, one thing I noticed, is that my dry fasts seemed to be a bit harder when I didn’t have creatine in my system for the days leading up to the dry fast. Lets say, if I didn’t take any creatine for a day or two before I entered the dry fast, it seemed like it was easier than going into the dry fast loaded with creatine. And btw, I normally take 5g a day.