In addition to the "Pro Pain Accessories" being a reference to King of The Hill, the pest control van that pulls up is the same one Dale Gribble drives on the show as well. The company is "Dale's Dead Bug".
The store front named "Pro Pain Accessories" is a nod to Hank Hill from "King of the Hill" and his "propane accessories."
Burger of the Day: For Those About to Roquefort We Salute You Burger
Second Burger of the Day: Oh Con-Pear Burger
Second Burger of the Day: Oh Con-Pear Burger
The main plot of the show is trying to establish the aquarium as a religious organization to be tax-exempt. But in reality, any type of nonprofit is tax-exempt. So they would only need to apply for 501c3 certification.