It is often a 5 dollar solution (actually less b/c you only use 1/4 or 1/2 bottle of drain cleaner for the unit)... 

To make move in / out run smoothly, you’ll want a good house cleaning service, carpet cleaner, pest control and landscaper.There are few ways to find these service providers.

I know you mentioned having the rent desposited straight to your checking account but I would have a separate bank account set up just to keep things cleaner. 

Appreciate the advice to a newbie.a) Do you guys give the tenants drain cleaners or something like that to put once a month to prevent plumbing issues.

This is the second time I have been taken to the cleaners -- (yes pun intended).  

Tell the tenants to use a bathroom cleaner on it once a month..should also take care of it.  

I would make sure everything is dried out then clean the area with a Concrobium cleaner to kill any present mold and prevent future growth from latent spores.

You're at out of state landlord, why not say that they've been great, the place is in great shape, and allow them to do it under the basis they hire a professional cleaner upon move out so you can sell it?  

Your cleaner and Airbnb make more money, but you definitely dont miss out on any.

Explain to them, the nicer/cleaner they make the house look, the more likely it will get rented and it'll be cheaper for them, stress it's a team effort!