The machine sprays drywall mud on the wall.  

However, Landlord makes no guarantees to the condition or function of the machines.

If the smell is still an issue, maybe try out an ozone machine.

Another option is to hire a carpet cleaner with a truck mounted machine.  

My wife's company uses a machine shop there.  

Here's a tip @Asury Johnson, when nobody is immediately checking in to a STR after a cleaning we make the beds with the damp linens right out of the washing machine.

Your agent should provide tons of info on the 'machine' itself - ie cleaners, repairmen, service choices (ie cable, internet, pests, CLEANERS)... if they don't - why are you using them!?

I have been using the Deal Machine app for a few months and love it.

Competition across the street does have rents at our potential estimated rents but a few more amenities are offered such as pool, pets, vending machines, etc. 

If her home is close to the retirement home, perhaps people could stop by the vacant house on their way to visit grandma or stay there if they live out of town and are visiting grandma.I'd also disconnect the washing machine.