Here’s the set of bone conduction headphones I got, it’s the hanging kind. The brand is “BAICLUD”, just your typical Chinese brand that may or may not disappear in a month: https://www.amazon.com/dp/B0D3LT2Q28
They are supposedly waterproof, so they may or may not do well with oil. In my case, they clean off easy and don’t seem prone to collecting grime/dust. I’ve no idea if there is a barrier under the physical buttons.
So far working well, though one thing I’ve found is that if my phone is in my back pocket and I crouch down or bend over, my body seems to interfere with the Bluetooth signal, sometimes interrupting it. No idea how normal that is with Bluetooth.
The sound will be bit different than regular headphones, but for me it’s not an important difference. I basically listen to Doom and podcasts.
So far I’d be perfectly happy buying them again.
I think an advancement to this style of headphones would be some way to adjust the length and tension of the connection band.
If they are loud enough to fully enjoy, then it’s going to outcompete your environment. You’ll need to have them a bit quieter than you’d like to retain actual awareness.
It's time I tried them. I have yet to find an earbud that doesn't fall out of my ear with activity. Plus, working in industrial environments generally means I need to keep at least one ear open, anyway. There's a market someone can corner; a bone conducting mono headphone that can deal with a wee bit of machine oil on the users finders when they need to start/stop the audio.