They need to visit Auschwitz like I did. (Rather) the teacher needs to visit Auschwitz and stand in front of the killing wall, view all the hair rugs, children’s shoes, prostheses, coats, etc.
And then visit the stand up cell where several prisoners had to stand all night in a small space. Then visit the open latrines in the middle of the three high cots, then visit the cremation center.
They would not deny the Holocaust after such a visit.
Oh, but yes they would.No disrespect to you intended, but intended for the deniers.