Yep, that's what I was trying to say. I have a friend who comes down to visit me every year for Dragon*Con, and she is so allergic to peanuts that if she eats something that was made on a machine that had recently processed food that had peanuts--say, a Hershey bar that had been made on a machine that had just processed Snickers--she would have a reaction. When she visits, I make sure to keep jelly on hand that I had not dipped a peanut-buttery knife into because that could make her sick.
Now think about Wembley and the bonkleberries. Just smelling them made him "bonk", which is a kind of sneeze, apparently. When he touched one he passed out. Who knows what eating one would do to him.
Let me guess!
They would make Wembley sick.
(Oh, and, TSSD--I'm female.
)