That seems the best alternative to me. If the host is so interested in enforcing the policy, let she enforce it herself. Given the circumstances, I think it is

That seems the best alternative to me. If the host is so interested in enforcing the policy, let she enforce it herself. Given the circumstances, I think it is highly unlikely Airbnb would charge the guest. In any case, the guest can also resort to a chargeback, as others have said. Not giving in to unreasonable demands should be the norm when using services such as Airbnb, Uber, etc.