I've used creatine a lot in the past and started again about 9 months ago when I got back into going to the gym. Never seen any penis-related gains from it...just the benefits you gain from it when working out.

Also if you are looking to boost DHT and testosterone creatine likely isn't the answer....arguably making sure you are getting enough D3, Zinc, etc would likely help boost natural levels more, but still any effect would be marginal at best. Hell if it did then people who do illegal steroids or DHT would all be well over 12" in size.