From Rocklopedia Fakebandica
South Park (first aired 8 June 2011). Kyle gives Stan their album for his birthday. Their music quite literally sounds like crap (with some synth beats in the background). Stan's dad Randy gets obsessed with it and starts performing Tween Wave as Steamy Ray Vaughn.
On Stan's iPod, it looks like it's spelled "Gersplush," but all other mentions of it use the two-o spelling.