We do not drain our hot tub after every guest, but we do test and adjust the chemicals, vacuum it (sand) and skim the top if needed after every guest. 

I have learned to get a cheap maintenance person and have them buy the good chemicals from A1 Able and spray it for you.

That includes weekly cleaning, chemicals, flushing of filter when it needs it, topping off the pool, and my people clean the pool deck when it needs it.

I used to work for a start up, we sold maintenance software to big oil and gas, chemical companies and other big producers.

Look at the topography and terrain to determine how.Evaluate fundamental infrastructure and service availability, as well as expose examples like wetlands and flood zones, protected lands, hazardous chemicals etc.

Everything I read online says DO NOT use exterior stain on the interior due to the fact it gives off harmful chemicals. 

You will get efficiencies of scale with chemicals and service calls.

Painting with Kiltz or Zinsser BIN will seal the smell, stain and chemicals for a while, but they may eventually come back.  

We washed the concrete with a garden hose and chemicals.

I joined bigger pockets a while back but had to focus on paying my way through school and passing a dual major in Chemical Engineering and Paper Science Engineering.