@kaia
I just smelled mine and they seem fine. They rarely needs cleanup too, I just remove the earwax a bit and that's all usually. So that's a unique issue I'm not familiar with so I can't help. You can probably just let the plastic in ear thing soak in water, but no luck probably for the "grill hole", if anything gets there, it's over

However, I have headphones and due to high eczema, lots of skin finds itself stuck in the cushion thingy, it's worse during the summer and when mixed with blood, it usually ends up smelling. Unfortunately I just change these once in a while