Upon move out, the tenant used the bath tub as a holding tank for his mop water, and whatever chemical he's used, he's managed to lift up a ton of the finish and it now needs to be completely re finished.

:-)I am chemical engineer by school, currently a sales manager in biotech as a day job. 

And some bedbugs develop chemical resistance.

You never know what chemicals might have spilled along the way.

I am sure he probably got shamed into it or realized that the harsher tone was probably not good for business.

I currently work at a chemical plant and I’m exploring the real estate investor world!

This is where the learnings pay off for me.My exceptions to do everything once: refinishing hardwood floors (seen enough diy debauchery), granite countertops and tub reglazing (cheap enough to have done and too specific of tools/chemicals for me).

But to be fair rentals are the smallest portion of anything we do.Where things like sealing and staining are concerned, a homeowner and products from box stores have no place and likely their knowledge is less than stellar when it comes to chemical compounds and one kind of acrylic vs another etc.

Additionally, I’ve heard a lot of chatter on this forum and AirHostsForum around cleaning procedure, recommended chemicals, etc. 

The majority of the rentals are chemical plant employees and most construction has been delayed.