I can't stand that odor

I got a roommate from foreign country, nice guy, accurate in payments but from time to time causing unbearable odor in the whole house. Like you suddenly stepped in stable that never was cleaned up. I am asking him, let’s find the reason and work it out and he is in plain denial. I suspect maybe it a spice but he swears he does not use spices. He persists he does not know the reason and blaming my kiwi juice or none-existing indoor pets. I never experienced such sudden and killing odor before him, and trying to figure out what in the world might cause it. It feels like acid blended with strong chemicals, and very hard to remove. I should keep all doors and windows open with AC running for couple days, and it still feels like every piece in the house have residual of it.

Anyone have an idea what source of odor like this might be? The guy is originally from asian country like Kurdistan and I already asked him to leave but still wondering what a hell is going on?

Never mind. My roommate left, we agreed to stay good friends.