The Guns N’ Roses frontman toured with the Australian group in 2016 when their singer Brian Johnson was forced to quit performing live after doctors warned him he was at risk of completely losing his hearing.
Speaking to the Los Angeles Times, Slash said: “The Axl-doing-AC/DC thing, I went and checked that out, and it was awesome. I was probably as sceptical as anybody because of the iconic status of the band.”
His initial misgivings cleared while watching his bandmate perform with the group, though. “He pulled it off and it was great,” he added.
In August, AC/DC were rumoured to be working on new music with Johnson and ex-drummer Phil Rudd, after the pair were photographed outside a recording studio in Vancouver.
Last month, meanwhile, a “reliable source” told Dallas publication JAM Magazine the band were working a new album that would feature their late guitarist Malcolm Young on “every track”. AC/DC were said to be planning to use old, previously unused recordings made by Young in the early noughties to create a new record.
Earlier this summer, Slash appeared to confirm Guns N’ Roses were also working on their own batch of new music. Speaking about the band’s future now they’ve reunited, the guitarist said: “Axl’s got a ton of shit that he recorded already, so we’re going to get in there and just start getting into that thing, and then if we do a record and then do a tour, I could see that cycle going on endlessly.”