@Jen-And-John0
Sending sympathy - we are also on a septic system and urban guests do not understand how they work, at all. This is a claim for your business insurance policy. They are already acquainted with your property and your business, and should be able to step in to repair the system. In the meantime, definitely get our excellent plumber out, and remove wipes from the bathroom. There is no such thing as a flushable wipe! They damage our septic systems and also clog up pipes at municipal water and sewage treatment systems. Definitely post educational signs in kitchen and bathroom.
Best of luck educating future guests, that is all any of us can do.