For the clear30-s, I did a dry burn and rinse after about 25 re-fills. I'm well over 50 refills now on the same coil, so probably will do another cleaning soon. I don't know how many times I refilled this tank now, I stopped counting once I hit around 50, and its still going strong with no noticeable drop in performance.
Never counted with the 16 and 30 to give you a good guess, not as much as the 30-s as far as I can recall, but long enough that probably 3-4 coil changes will get you by for at least a few months, depending on how much you vape and how often you refresh the head with a rinse and dry burn.