Dish soap/washing up liquid. As you’ve already washed them get it well scrubbed in and let them soak for a good while.

They could, it’s extremely unlikely outside a few certain areas.

Edit. It’s also illegal to carry a knife unless it’s less than 3” long and folds, like aa Swiss Army knife or similar.

I live in the UK, I will not make this assumption as it would be stupid. Other countries exist.