The easy solution is to leave an intriguing white stain on the front of your seat and a brown stain near the back of your seat. (Vanilla and Chocolate pudding might work)

Then chain the chair to the desk.

Noone wants to sit in that chair ... but they can't move that chair to bring in another.

I am definitely not a fan of hot desk. I have 15 years worth of treasures piled on my desk. If there is a famine, I can find a chocolate bar from 2005 if I really need to. There might also be a bottle of rum that's been in one of my drawers for over a decade.