During the times when the Hulk is calmed down and has changed back to Bruce Banner, why has nobody thought to castrate him? He won't become the Hulk again if he can't get good and mad.

What I don't get, is that they can create a million different power dampeners that will work on every other character in the Marvel Universe (including characters with similar powers,) but they can't cure Hulk or Thing. WTF?

Have they ever tried a complete blood transfer, even a bone marrow if needed. Seeing how dangerous he can be they could even harvest and replace all his major organs with that of a doner. Could that possible do the trick? I'm sure if it was possible SHIELD would not mind forking over the means.

Bruce Banner had a gamma ray machine which would have ended the Hulk forever, but the Army misunderstood him and thought he was trying to change back into the Hulk again. Then a spy used the machine instead of Bruce, creating the Abomination. The Silver Surfer said he could rid his body of all his gamma cells, making him normal again. But the Hulk thought he was attacking him, so he punched him causing the Silver Surfer to leave. I'm sure there are lots more, but the plot usually won't allow it since there would be no more Hulk afterwards.

Tylenol and Moltrin works pretty well for me...

paint him peach when he turns into the hulk and let him look ina  mirror. (maybe throw some pon pon's in there)

" @Power NeXus: If Mephisto offered Bruce a cure for the price of his soul would he take it? No loose Hulk just Bruce in hell "

Get Anti-Venom to sneak up on Banner, and he won't have time to turn into Hulk. 
 
... I think. It could end with Anti getting thrown into the moon.Lmao.

 
Robert Grayson had a suggestion in Agents of Atlas but they bailed out on Banner due to an emergency.