Which of the following sentences is most grammatical for US English, or are all of them ungrammatical and should be written differently?
I will not allow anyone to do something to him or her.
I will allow no one to do something to him or her.
I will allow anyone to do something to neither him nor her.
The intent is to state that the speaker is going to prevent anyone and everyone from taking an action as regards to "him" and "her".