A wet test does not constitute commercial use. Commercial use would be making someone PAY to use the tub.
Acording to the health department there are two types of applications.
1. Residential :consisting of a spa installed in a single family dwelling for use by said family.
2. Commericial: All other aplications
I might not be the smartest guy around, but I don't think that letting a customer come into my retail store and use a hot tub there would fall under Residential use.