FX FOOTBALL CROWD.
FX TANNOY BONG.
STADIUM ANNO
(muffled voice): Thwould da perthon in da main sthand thop thowing thoilet throlls pluease.
Stadium Quickie
eh?
No, ok.
Surely they'd need to be in a baseball park for it to work properly?
Kind of works in a throwaway one-liner in the background of a proper sitcom, but not as a sketch itself.
Go rewrite your 'Nativity' one -- that's awesome! 
Dan
Ah now I get it, did you edit that?
Not bad joke, bit badoom tish
???
??? Indeed, but maybe:
FX FOOTBALL CROWD.
FX TANNOY BONG.
STADIUM ANNO
(muffled voice): Thwould da perthon in da main sthand thop thowing thoilet throlls pluease.