There are many out there that aren't worth their salt.

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

The companies that use heat treat in this area usually charge a lot more than chemical sprays.

When you are doing some 35 campaigns, often 3 sets per day over 30 days you will be getting replys sprayed back pretty evenly. 

I even outlined the spot in orange spray paint.

I would always take comments like "I have friends who say..." and probably heard from someone else with the necessary pinch of salt.

You can replace the tiles or spray them all for a fresh look.I would question having a 'Contractor' who mows your lawn doing other work.

If there are any issues, we send out the pest control to spray, and guests will seem happy as long as we attempt to fix the issue.

Based on what you've provided here, I'm going to assume the partner is a friend or family member- and not to rub salt in a wound, but most people think that makes a contract LESS necessary, which is the total opposite.

Take a sandwich, apple, drink, and weed spray and do your loop once a week.