Kelly McCaughan may no longer be a practicing Catholic but finds it understandably difficult to escape an institution that dominated her entire upbringing. It’s far easier to wash away the idea of sin than it is the ritual and iconography of the church. But the fierce and irreverent McCaughan is determined to deal with the weird hold that her erstwhile faith has had on her life, and her iconoclastic hour ‘Catholic Church’ functions as counter-ritual and sexually-charged cleansing experience. It would also probably get her excommunicated if she hadn’t left the church of her own volition.

McCaughan has been sculpting this show for some time now yet you get the impression every show is like a sacrilegious anti-pilgrimage for her, one that just happens to be often hilarious and full-bodied enough to slightly scandalise those with even the loosest of ties to their god. She goes through the basic tenets of Catholicism and details how they were enforced throughout her childhood, complete with photographs and a breakdown of the 10 Commandments, complete with liberal splashes of holy water.

Kelly’s performance is confrontational and fuelled by a knowingly exaggerated eroticism that she mines vigorously for uncomfortable laughter from the audience. The level of crowd interaction is high and she gleefully wrings every drop of cringe from a reenactment of her first kiss with a visibly stricken man she’s hauled onstage (the first chap she asks gets such a ‘Don’t you fucking dare!’ look from his partner he gallantly demurs). It isn’t a show for the socially awkward, and there are several instances of people obviously not knowing where to look. All grist to McCaughan’s devilish mill.

There’s nothing surprising about the direction McCaughan takes with ‘Catholic Guilt’, but the lengths she takes it stretch as far as the Camino de Santiago. She’s fully aware of the semiotic power of Catholic iconography, and is brilliant at subverting that imagery, not least in her stage outfit of traditional Catholic schoolgirl uniform. Of course the shirt’s been tied to bare her stomach, and the skirt is a good few inches too short for official regulations. She goes on to frame the loss of her virginity as a moment of pure religious transcendence backed by the ecstatic swells of Barber‘s ‘Adagio for Strings’. She also co-opts Nine Inch Nails iconic perv-anthem ‘Closer‘ as a backdrop for a montage of ‘Hot Jesus’ pics, the homoerotic inference strong enough to make Tom of Finland blush. Yet it’s the finale that really nails the extreme heights, one that shouldn’t be spoiled, but needs to be seen to be believed.

Not quite a comedy show, and not quite theatre, but some fusion of performance art, burlesque, one-woman bildungsroman, and outrage comedy, ‘Catholic Guilt’ is brilliantly performed, genuinely shocking (not an easy feat at the Fringe), and a work of extraordinary boldness. Kelly McCaughan is in full control – even able to brush away a couple of technical issues as Satan being in the room – and is mesmerising to watch. Structurally, it’s a simple narrative that plays out as you would expect of a young woman who slowly comes to reject her faith, but the presentation is something to behold.

‘Catholic Guilt’ runs until Sun 27 Aug 2023 at Underbelly Bristo Square – Daisy at 22:15