What it was was weird. He started out with some family history, about his mother's experiences as a Holocaust survivor. I actually got confused about what happened to which family members, but the gist was that part of his family was very Jewish and the rest was completely terrified to let anybody know they were Jewish. His mother fell into the latter camp and married an Italian Catholic. So, basically, Slash grew up conflicted and hiding his Jewish-ness. The show is supposed to be about his trying to find a way to complete his Jewish identity, which he does by trying to find the second triangle to turn one he wears on his t-shirt into a star of David.
Unfortunately, it got fairly incoherent from there. He did a bunch of audience participation stuff, but not all of the people he drafted to do things seemed all that willing. He had a bunch of "halfie" jokes, which were fairly incoherent as well. The shticks included giving birth to a giant matzo ball and a stint where he dressed as Jesus to explain Jewish geometry.
Things improved somewhat when he abandoned the costumes and shtick and talked about his conflicted feelings. His telling about his nephew's growing interest in Judaism was warm and could be developed into a real story. But this was too clearly unscripted and not really audience-ready. The cardinal sin of storytelling (as far as I am concerned) is committing therapy in public and that's what this felt like.
Bottom line is that there are bits and pieces of promising material, but the show just didn't work for me.