According to Kevin Smith and Jason Mewes the origin is this: When
Jason was younger, about
14, he used the "nee"-expression as a means of countering a statement just made, as in "I'm gonna fuck your mom tonight - nee". The "nee"-expression then grew and grew, but always refering to the canellation of "charge" in a statement. Thus, snoogans means to not do anything. Just the same as
Wayne'
s world's "not!"-expression. Of course the snoogans works excellent as a stand alone-expression, but the "true" ethymology is the
one stated above.