The phrase originated in the backwoods of Maine. "The Scrooched Moose" is the act of wildly thrashing about as you rapidly change through sexual positions. If at a campsite the scene left behind will look as if a wild bear ransacked your tent. If indoors the scene will look as if you had been burglarized.
A man at the bar was bragging to his buddy l; "Hey man, last night I finally got The Scrooched Moose treatment.".
When someone finally drops the final straw that breaks the camel's back and you do every conceivable action within your means to destroy that person's life in its entirety, short of killing them.
When an army is retreating, destroying everything that could be of use to the enemy as it goes ie: railways,bridges,buildings,power,oil instalations etc etc so all that falls into the enemys hands is wreckage&land scorched by demolition charges.