DHT is in fact what is used in FTM situations and in cases of microphallus. There are problems however. Inside the United States the most commonly used Rx which is Andractim Gel is not available. Any of the compounds used here are made by compounding pharmacies. This gives U.S. guys a problem from the beginning.
There could be a percentage who indeed would respond, but, this would not be true across the board. There are a number of factors that would have to come together in an individual to make it possible.
At the same time:
DHT is a controlled substance and though I do know of individuals who have ordered it off the internet and received it on U.S. shores, it is illegal and can have the DEA knocking at your front door.
All I can tell you is that it is expensive with no guarantees. That being said, possible indeed it is, likely, I really don't think that most would profit from it.