Before the do not call list took effect I had my own way to discourage them. All of our family and friends knew about it and got a kick out of it.
I had several lines.
Hi, Joes bar and grill, can we get you fried tonight?
Mike's house of pain, where we're not happy until you are crying.
Franks cat house, where the customer comes first.
Greg's whip emporium, where only your plumber has a bigger crack.
We seldom had any telemarketer problems.