Hi @Mary641
You need to discuss the Roles and responsibilities with the guests.
You can agree with extra cleaning - maybe halfway their stay - but I understand about not wishing to go to their space. So leaving the cleaning products available for them, and telling specifically that they should leave the property in a clean state when leaving.
I would suggest you draft a short term agreement, to have it signed by the guests.
Also, record the state of the property, maybe when walking the guest thought the property, just in case something get broken or goes missing.