British comedians Bridget Christie and Stewart Lee
Hello! Something I found by the off-chance after I saw the name "BRIDGET CHRISTIE" as one of the supporter names on Birthing (top right, in caps on the last insert), and thought if it could be the same person as the British comedian. Turns out, it is! She even posted about them on insta with Swans_official liking her post.
https://www.instagram.com/p/C4U72kJM4JQ/
She also went to the final Berlin show - https://www.instagram.com/p/DRreOa8jRIM/
She was also married to fellow comedian Stewart Lee. In his 2019 book March of the Lemmings he mentions this about a visit to Seattle in 1994 where he met a scenester (page 65) - "He seemed normal enough by the standards of the day - beanie hat, goatee beard, and pierced nipples poking through a t-shirt bearing the legend 'Public Castration is a Good Idea'".
On another note, I saw Lee live last year and wore that t-shirt to the show. It was an ice-breaker during the meet-and-great afterwards! :D