The correct order for treating surfaces with antimicrobial pesticides generally involves the following steps:

1. Cleaning: First, physically remove visible soil, organic material, and contamination from the surfaces. This is essential because dirt, oils, and other materials can interfere with the effectiveness of antimicrobial pesticides. Cleaning often involves using soaps or detergents to bind and rinse away soils.
2. Sanitizing (if applicable): This step may be used to reduce bacterial contamination to safe public health levels but does not eliminate all microorganisms. Sanitizing is more common on food contact surfaces.
3. Disinfecting: After cleaning (and sanitizing if applicable), disinfect the surfaces by applying the antimicrobial pesticide. This step destroys or irreversibly inactivates most pathogens such as bacteria, viruses, and fungi on hard inanimate surfaces. It may involve wiping, spraying, fogging, or soaking small items.
4. Contact Time: Ensure the treated surfaces remain wet with the disinfectant for the full contact time recommended on the product label. This is crucial for the efficacy of disinfection.
5. Rinsing (if required): Some antimicrobial pesticides need to be rinsed off after the contact time to prevent harm to animals or people.

Additional tips for application:

• Work in a systematic manner, typically from the cleanest area to the dirtiest, and from high to low surfaces.
• Pay close attention to corners, cracks, crevices, and other surface irregularities that may harbor pathogens.
• Floor drains or similar areas should be disinfected last.
• Wear appropriate personal protective equipment as indicated on the product label.
• Always follow the label instructions for dilution, application method, and safety precautions.

Summary: The key to effective antimicrobial pesticide treatment of surfaces is "Clean first, then disinfect," ensuring the correct use of contact time and application method to maximize microbial kill while following safety guidelines. Without proper cleaning, disinfection will not be as effective.