You don't have a efficiency problem, you have a cleanup-old-mess problem.

Like I mentioned, I've only charged someone the towel fee one time and it was because they used bath towels to clean up the kitchen (not the guests I want). 

If the exterior gives you pause, you might  need to check in with the tenants yourself, require them to clean up, make repairs etc.

There has also been awarded a No Further Action letter related to years of monitoring after cleanup.

Thicker drywall (5/8s instead of 3/8)Stain resistant paint or at least easy to clean up paint (this may vary cause in most causes tenants put so much holes and dents in walls, the turnover for rentals usually require repainting anyways)Easy to clean back splash (less grout = less stuck dirt, so consider the size material)Countertop type (granite and marble stains and require to be polished and resealed eventually; quartz is stronger and stain resistant, but cost twice as much)For appliances, I suggest going to local appliance stores not big box stores.  

If you are nervous about depleting your savings think about how you would handle any unexpected repair.  

I will clean up the leaves just like I did a couple weeks ago and removed 6 waste bags.

I am confident I can sell it for easy $100k over what it is listed for... in May... with just some flooring and general clean up... 

@Eric M.Leveraging is a great way to grow your portfolio without depleting your own cash however there is definitely a certain array of caution that needs to go into it. 

I think this will be the fastest and most cost effective way clean up the walls.