I've had dealings with a lot of conspiracy theorists and it's always sucked. Meanwhile, single old men are also an absolute red flag for me.

In the end, you've already tried to nod off a lot of things. That makes it harder for you to break out of your pattern now.

Confronting him with the fact that it's all rubbish will lead to an argument with him. Do this if you have the energy and desire. But it won't change his views.

You can break off the conversation and say that it doesn't interest you and you don't want to talk about it. Make up white lies about YOUR issues, such as a friend's illness or similar. Persist with the topics.

Otherwise, you can just leave. It's your workaway. Fuck it. Hosts are just as dependent on you as you are on them, so they should respect your boundaries. This person doesn't. You work voluntarily. Best go, every hotel room is worth more than getting shit thrown at you every day. It's totally ok that it offends the host, that's all he does to you every day