"Schissdreckzügli" is a small group of people celebrating "Fasnacht" (=carnival) on the street. It is not important, how well one plays an instrument, or if one plays an instrument at all. The aim of such a "Schissdreckzügli" is having just pure fun and enjoying carnival.
Many active carnival members do not want to spend the whole "Fasnacht" only with their "Clique" (= carnival group), but they would also like to walk through the streets playing their instruments ( "gässle") with their friends from other groups. The solution is to form a "Schissdreckzügli". But very often the musicians of the different groups do not know the same pieces of music. This does not matter in a "Schissdreckzügli". One just lets the others play and joins in again later. In an ordinary "Clique", however, this would rather be unusual.
To form a "Schissdreckzügli" is a possibility for a family with children to have fun and to satisfy their wishes and needs at the same time.