I already apologize for taking such ugly sentence but I have no other choice as that’s what brought the question to my mind. Just read this in Urban Dictionary:
I don't know what he ate, but man, he blew up the bathroom! You won't want to go in there for a while.
1st, I know it’s possible to put “don’t” in place of “won’t” here, but don’t know how that would affect the meaning.
2nd, is using “in” optional here or it adds some meaning to the sentence?