It is more a guest problem?? Well, no - if I(or my cleaner who I pay for) am the one who has to deal with that mess, it is not only their problem.
I have hosted more than 2000 guests and tried many different ways in my 5 years of hosting - the best message worked was "I waved cleaning fee cause I expect you to clean the place before check out. If you don't clean up after yourself, I will charge the cleaning fee."
When I charged some cleaning fee, it was very much of a hassle as well - when I claim the extra cleaning fee through resolution center, they would argue that I already charged the cleaning fee, etc. Bigger the amount, more toubling with cleaning as well. With smaller cleaning fee, I get more shorter term bookings. This is why I don't like the term cleaning fee.
And you really need to know (if you don't know, you are soooo lucky and I really envy you) that guests don't read House Manuals/Rules anymore......