Weirdest Research Subject?

The Eötvös effect, and its relationship with the Coriolis effect. Most people are aware of the latter but few have heard of the former.

I was researching assisted suicide via nitrogen asphyxiation for a SF story set on a planet with more than the 78% nitrogen we have here on Earth. I got all sorts of suicide prevention warnings in my Google results.

Usenet Beastiality FAQ

I don't think the hottest human female could interest me an any form of sex where protection meant a hard hat and steel toed boots.

Stab wounds, fatal

The smell of gangrene

Herbal abortificants

If you could survive being underwater in a tsunami. SPOILER: there's a very slim chance because it would be like being in a washing machine.

I'm eleven years into writing a Theory of Collective Ignorance, as adult potty humor based on the 12,000 year old Bagua, that expresses countless ways to prove with quantifiable empirical evidence that reality is stranger than fiction according to academic standards. This includes a way to prove the Quantum Observer Effect is due to each of us determining our own local reality to some extent, just as each of us has a meager gravitational field we share with the rest of the universe. However, a major implication is that civilization tends to organize like chickens, because lowbrow slapstick is intrinsic to nature, and academics everywhere hate me for writing a book that forces them to confront their own lowbrow slapstick. They have my sympathy, but somethings are best gotten over with quickly, and their experimental results are already transforming into a mountain of lowbrow slapstick of epic proportions.

Teen grief. Not so much weird but when I have nothing to do with it, then it's weird.
I was working with a subject where the younger brother is dealing with his older brothers death/possibly murder by police in a healthy way that is apparently unhealthy by the conclusion. I was at work and the wife bumped my desk, shifting the mouse, and the 3-monitor set-up screens came on showing multiple windows of teen grief and loss and treatment. So I get a phone call while in a hotel.

"Um, honey, is there something I ought to know about? I'm seeing things on your computer screens..."

Loads of stuff like how to make a bowstring out of rabbit gut or how to brain tan hides or how to light fires with friction or flint and iron pyrite. How to use fire to straighten a middle palaeolithic spear shaft or how to make a levallois prepared core spearhead (a particular middle palaeolithic flintknapping technique). It's not that weird though. A lot of people look up stuff like that in case there's a zombie apocalypse. Interest in palaeolithic life and writing palaeolithic fiction seems quite tame in comparison. And flintknapping is a craft in its own right.

More weird though is the number of people who find my blog after searching for "neanderthal sex" ... umm, yeah, that boat sailed about 28,000 years ago...