Crazy Handful of Nothin' - S1-E6
Trivia: When Walt blows up Tuco's office, listen closely. Mixed in with the screams is a distinct sound of a man shouting "Yeah!" That is a clip of the infamous "Dean Scream." In 2004, democratic presidential hopeful Howard Dean let out an excited "Yeah!" after giving a rousing, over-the-top speech. However, his giddiness and the scream were viewed as unprofessional by the public, and the moment briefly made Dean into a laughing stock in the media. The scream then became an infamous soundbite.
Chosen answer: It is part of the ritual for la Santa Muerte. It is a sign of humility and sacrifice.
djm