@Stacy-And-Tim0 one option is to ask the guest to withdraw the request, explaining that the rule must be followed, and if they don't withdraw the request you will assume that means they agree to follow the rule, and will accept the request with the strict provision that they will not break the rule (and any rule-breaking will result in immediate eviction).
Others will argue that your decline rate doesn't matter, won't affect search placement, etc.-- I am personally not so sure about that.