I’m in the camp of not trying to cover funky closet smell with any fragrance. If you can’t put freshly laundered sheets on the bed I’d try spritzing with vinegar water, or as I was just wondering…can they be freshened on the steam setting on my dryer. Or just spritzing with vinegar water and putting out on the line or in the dryer.
I have a problem in the summer with bugs getting on the linens. I’m fine with my own linens but if any bug snuck into the bed without me noticing and then the guest found it, that wouldn’t be okay.