(Must be off season..currently researching how our beloved mascot's name became a term used to describe an interception..)
The Oski Wow Wow yell was used at Cal from before 1900. When I was at Cal in the 1960's I was on Rally Comm and talked with a woman yell leader from the 1930's. She said that the Oski Wow Wow cheer had been used from time immemorial. She said it had been patterned after the Ivy League cheers of the 1800's such as Georgetown's "Hoya, Hoya" cheer.
Several years ago when I was flipping through the pages of a Blue & Gold from some year in the 1880's-1890's I ran across a comment that the Berkeley students were demonstrating outside of a Berkeley City Council meeting for Berkeley to change from a "Dry" (no alcohol) city to a "Wet" (alcohol) city. At the demonstration the Berkeley students let out with an Oski Wow Wow cheer.