A compound pseudo-German usage of 'Schitz', which means "to slice/segment" and 'Grüb', which is a truncation of "Grüben" meaning to meet yet really a corruption of 'Grub' meaning "to dig/pit".
It is an alternate form of the usage "
Schnitzengruben" from the movie Blazing Saddles, and as such may have elements of humor (including
double entendre) involved.
It is simply another way of saying "aw shucks" or "cut the garbage". It is also a hearty
alternative to shouting expletives and cussing.