I don't want to loan my bed to a random subleaser
Why are you renting you bed to people?
I need the money and I think it's disgusting and unpleasant.
You should be willing to help someone out if they need a place to stay and they're leasing from you. Try to come to an agreement about showering and see if you can come to a mutual agreement.
I'm just not willing to share the bed with him. He's weird and gross.
You can always offer a sleeping mat for that person to sleep in. It's better than having him sleep on the floor.