Tea that makes everything taste like dirt
This sounds like gymnemic acid, which can be isolated from the leaves of Gymnema sylvestre. It’s an “anti-sweet” compound, which wouldn’t necessarily make everything taste like dirt but might do so for you particularly. When I had it, it made my tongue slightly numb and candy tasted like nothing rather than sweetness, so it may not be what you’re looking for. 

Lactisole (from coffee beans) is another option, but I haven’t tried that one personally so I’m not sure what its taste effects are like.