I don't endorse what I'm about to type in the slightest bit, just wanted to get that out of the way first.
A friend of mine swears by wrapping his seatpost with barbed wire sectioned with regular wire, so it's basically 1/4's he turns the wrap when he gets somewhere so the barbed wire parts are pointing out towards the thighs, and turns it back when he hops on, seems dangerous and stupid to me but it's what came to mind.