I could be one of the few that is against duct cleaning cause of the after affects of the brushs might cause on the thin inner tube of your flex ducts.
I will recommend that that you go to the cause of your problem and that is your evaporator coil. Have it profecionally clean and sanitize. Split systems need to be pull and clean and package units could be done in place. Pull and clean unit clean are more costly than package units cause there is more work involved.
Koolray heating and air