re: Residential A/C Maintenance - Baton Rouge - what company would you suggest?

Very few companies disassemble the cabinet of the condenser unit outside like you are supposed to in order to do a proper cleaning. Most techs just spray chemical through the louvers as best a they can and rinse. Yes, better than nothing but still the workmanship of a hack.

I would ask that question and make myself available to witness the cleaning to see if it is done properly. They should also clean your evaporator coil in the attic unit so someone will need to be home either way.

Or, do like I do and do it yourself. If you do a thorough and proper cleaning, once a year is plenty.

The best chemical to use is Tri-Power HD. It is made for the evaporator and the condenser.