I’m not Jewish but I wanted to weigh in on this because I think it’s worth considering a few things:

1. Saying “Go to hell” as a turn of phrase is really commonplace and it isn’t going to be any more anti-Semitic than anything else.

2. If you are making a theological statement like “Zionists are going to hell” to Jewish Zionists then that’s not going to carry much water because it’s incompatible with the Jewish faith and it probably means as much as if someone said to you “Allah is disgusted with you”; for one thing, as a theological statement, you really shouldn’t be speaking for God if you are a believer and on a more mundane level saying something like that has big “Well, my dad could beat up your dad” energy.

3. I think that your words would have a lot more sting in their tail if you said something like “The words ‘Never again’ didn’t come with a subclause” or “Your actions dishonour the memory of those who died with the words ‘Never again’ on their lips.” Of course, this will get you accusations of anti-Semitism in response but that’s neither here nor there.

(There’s a good Jewish anti-Zionist organisation called B’Tselem, which means “In God’s image” and that’s a theological statement about how all of humankind are God’s children. But I have to wonder if there’s subtext to imply that the work they are doing is their effort to act in God’s likeness [i.e. something along the lines of “We are doing this as God’s will”] but also to pose the rhetorical question to Zionists by asking “Are your actions truly a representation of God’s likeness?”

I don’t speak Hebrew and I’m absolutely not a Torah scholar so that’s just me spitballing but I do wonder… at any rate, I think that if you’re going to make a theological statement then there are better ways to go about it than to threaten Jewish people with something they don’t believe in but I think it’s even better not to make a theological statement in the first place.)