'Matchstick-up-the-butt' [Jillian Rogers, Yukon News - March 8, 2006]
Training a dog to poop on command is challenging at best, so Rex Jones uses the old 'matchstick-up-the-butt' trick.
"The irritation of the matchstick helps them clean their system and therefore run a better race."
[Rex Jones is the owner and operator of Arctic Paws Kennel and Sled Dog School in Chugiak, AK. He was teaching young mushers at the Arctic Winter Games in Alaska (2006) this 'mushing secret.']