Just like a practitioner's office, an ambulance is a medical environment. The potentially high-intensity contamination requires specific attention.
Cleansing with ozone-treated water is one option. But the greater necessity is to protect paramedics and future patients from contracting contagious disease by intensely disinfecting the air while the vehicle is unused.
Higher concentrations need to be applied in such an environment - and in closed quarters. Treatment times and post-treatment times and protocols need to be rigourously studied. Units intended for household use are not adapted for this type of use.