Back in the early 70's a cousin of mine who weighed more than he should for a highschool kid, bought a small motorcycle (less than 125 CC's but I don't remember the actual size, probably something like 80 CC's) and put a can of STP oil treatment in the oil that also was the oil for the wet clutch. That poor little clutch slipped so bad it would not even go up a small slope of a hill. The STP oil treatment was very thick oil. It flowed out of the can like very cool honey would flow. And considering that the small engine on this small bike did not hold all that much oil in the first place, meant that the can of STP oil treatment made up a considerable amount of the oil in that engine.
He had to take the entire engine apart and clean every part, and then put it all back together. It was a long project for someone who was fairly new to working on anything with an engine, and basically the entire bike spent the winter in pieces stored under his bed. But he got it back together in the spring and it ran fine.
So yes Virginia there is such a thing as oil that will prevent a wet clutch from working. But if you want to recreate this problem, probably half the problem is having an big person on a bike with a very small engine, and therefore a very small clutch.