I think ozone will be your best treatment, however you may need to hire someone that has commercial grade ozone equipment.If I were to do it over again I would ozone, spray probiotic cleaners and let sit for several days.

.- Another change I made is around prebiotics and probiotics.

I add probiotics monthly, clean the filter about every 4 months and have it pumped every 2 years.

The pine oil loosens debris and helps keep things moving...kind of like a healthy intestinal track when you use probiotics.  

Spray with a probiotic enzyme....let set for 3 days than ozone overnight with all cabinets open and air conditioner on to pull thru ductwork.

I digest all fruits and veggies without a problem, because I make sure I have plenty of protein when I eat, and I also take probiotics.

At my age and with my desire for multiple cups of am coffee, probiotic drinks, road cokes and plenty of water I'm a frequent potty stopper and would certainly hate to be stuck somewhere without the ability to take care of biz.All that stated that still leaves business and pleasure travel i.e. flying, international travel and cruises which we refuse to relinquish under any circumstances.