> Having a question about the HC makes you a non-believer
I did not see you ask any questions, only state your doubt.
> I also say that I personally can not verify it,
Yes, you can. Find some camp survivors and have a chat with them, then wonder how we will remember when the last ones have died.
I think you just did push me into the revisionist camp. I did not make a claim, except that there are people who deny the Holocaust. I also say that I personally can not verify it, but that is not making a claim.
Merely taking up the discussions means that you will mention arguments of the revisionists, which will end up making you look like a revisionist. Having a question about the HC makes you a non-believer.