They sell this product manufactured by REX-BAC-T Technologies right at their table. It brings homeowners to the table and the sales end up paying for more than the cost of booth.
Give them a try.
You can private label them with your home inspection business logo and contact information so that repeat business comes directly to you. If you do home inspections on homes that have septic systems they provide and opportunity to educate your clients about their septic systems and make additional income.