Doutch is a term used for someone who is both dutch and a douche. It is said to be one of the worst combinations on the planet for obvious reasons. It is commonly mistaken for Doutch-Bag, but this is completely different.
Doutch-Bag is a prank that started around the late 1930's, but reached it's popularity in the mid 1960's. The prank is when a person or group of people fart in a brown paper bag. After every has took a took a turn, you ask a Doutch to smell the bag by tricking him/her. You must have a clever reason in order for him/her to smell. After he/she smells the bag you have suceeded. Warning: no urinating or making a bowel movement in the bag. This is considered dishonourable and highly frowned upon by many.