Controversy seems to follow Insane Clown Posse around. The Detroit “horrorcore” duo have seen albums pulled from shelves and their army of fans, the Juggalos, declared a “gang” by the FBI. On their first UK visit for 14 years, the entire tour is pulled at the last minute, leaving them scrabbling around for alternative venues.

Then the opening date, already switched from Leeds to Sheffield, was further postponed because their equipment had gone missing. All this left ICP – who wear the tag “world’s most hated band” with pride – raging about persecution. However, in true theatrical style, they insisted, “the show will go on”.

When it finally does, theatre and showbiz are indeed what they’re about. ICP’s masterstroke, which brought them 6m album sales, was to dress like horror movie “wicked clowns” (also a nod to real-life “killer clown” John Wayne Gacy) and fuse hip-hop, metal and deranged carnival music with violent nursery rhyme-type raps about serial killing and such.

Although there have been isolated incidents of Juggalo violence in the US, most fans find the duo’s lyrics darkly entertaining or strangely cathartic. But in 2017, when everyone from Tyler, the Creator to Future are genuinely disturbing, there is less shock value in My Axe (“is my buddy”) and Crooked Preacher Killas, or the duo’s cheerily delivered lyrical procession of bogeymen, “dicks” and “motherfuckers”.

It’s certainly not music for small children – but the atmosphere is indeed like a crazed kids’ party hosted by two creepy but amiable uncles. Violent J and Shaggy 2 Dope (in full clown makeup, as are many of the fans) spray everyone with soft drink Faygo and deliver their trademark “Whoop whoop!”, while Fuck the World brings comedy to nihilism (“Fuck everybody! Fuck you! Fuck us!”).

The party atmosphere takes a peculiar turn when several women are invited on stage and grin and dance through Cherry Pie (sample lyric: “I need a bitch, who likes banana in her butt”). Truly Alone’s startling depiction of a potential suicide (“There ain’t nobody making sure I’m taking all my pills / I’m truly alone”) is eerie and strangely moving, but the moment passes.

“Are you ready for some Faygo?” yells Shaggy, as entire buckets of the stuff are hurled over the giggling Juggalos. The people who should be most appalled by Insane Clown Posse are the cleaners who have to mop it up.

• At the Garage, Glasgow, on November 15. Box office: 0141-332 1120. Then touring.