Oh, they say that? Weird, I distinctly recall the box saying “reusable” when I bought them years ago. I guess it’s like the thing where Q-tips are labelled as “not to be crammed into your ear-holes”, to bring it full circle.
I clean them using a hand bidet, the high-pressure stream of water from it blasts all the wax out from between the vanes. Soaking them in some kind of soapy water or solvent sounds like it’d work well too, if you don’t have a high pressure water stream readily available.
It’s bottoms all the way down.