Basically, they don't know what the fuck they are bullshiting about. Do us a favor and ask them what "cleaning exhaust" entitles. It would be a great service to the community here in case we were missing something.
If you have a choice not to use them, make sure you do NOT spend a dime at that scumnest and also make sure that you stop by at the manager's office to let him/her know about it and why.