There's plenty of videos of Dupuytrens patients getting their hands fixed very rapidly. They get the shots , then a day or three later, the doctor does some aggressive "modeling" and pretty much straightens the hand quite rapidly.
Here's one:
https://youtu.be/SwcjmxVfGSg
If only it was this straight forward (no pun intended) with the penis. There probably isn't a way to rip apart the scar tissue in the penis like you can for fingers and hands. And you'd have to worry about a fracture too.