Cat humped my squishmellow how to clean and what replacement object

Hi,

Yes this is serious

So my male neutered cat has started humping my squishmellow. I saw him this morning I didn't know what to do so I just let it continue I didnt want to chastise him for what I assume is instinct behaviour. How do I clean the squishy and do you think there's anything I could replace the squishmellow with that would be as soft? I'd obviously rather he used a designated blanket or item.

So * how do I clean my squishmellow * what soft item would replace my squishy but is equally as soft?

Thanks