The "scuz" (rhymes with "fuzz") might come from "disgusted"; really with-it slanguists are scuzzed out at the squared-out weirdos who still use "grossed out."
1999 — Thomas Doherty, Pre-Code Hollywood: Sex, Immorality, and Insurrection in American Cinema, 1930-1934, Columbia University Press (1999), →ISBN, page 181:
The inability of slow-witted censors to keep up with the implications of fast talk from "ultra-modern slanguists" made for a fun game of hide-and-seek between the hip and the hapless.
2005 — Charles Harrington Elster, What in the Word?: Wordplay, Word Lore, And Answers to the Peskiest Questions About Language, Harvest (2005), →ISBN, page 214:
Slanguists generally agree that it probably comes from an ancient monogram for Jesus, IHC or IHS, in which H is the Greek capital letter eta, a long e.