@Stacy364
First, there is no security deposit unless you took one separately.
Second, the loss of the bathroom rug should be a small amount, and that can go into your cost of doing business expenses. I designate a certain amount of rental dollars for replacement costs. It is not worth asking AirBnB or the guest for reimbursement of nominal costs. It won't be paid.
Thirdly, be honest in your review of the guest and do not fear a retaliatory review. Your review cannot mention the feces, but you can state that the guest was not sanitary and left your property in deplorable condition. This guest may leave an ugly review, but generally they rant so much that other guests will "see the crazy" and ignore it. Prospective hosts will appreciate your honest appraisal of the guest.