Duff played on Alice In Chains "Facelift"???

I was totally unaware of this..Does anyone know if its true? Like is he on the actual "Man In The Box" that is on Facelift?

"KURT, GRUNGE AND ME"
VR's Duff McKagan on his punk past and a fateful night with Cobain. By Paul Elliott.

"I was totally aware of what was happening in Seattle in the early '90s," states Velvet Revolver bassist Duff McKagan, who'd grown up in what was to become the epicentre of grunge.
As a teenager, Duff cut his teeth in all-manner of local punk outfits (29 at the last count!). A brief stint drumming with The Fastbacks between '81 and '82 saw him switch to guitar and form Ten Minute Warning (the band he'd re-form in '98 after his exit from Guns). He then moved down to Los Angeles where he hooked up with Slash, Axl, Izzy and Steven Adler. His return to Seattle with Guns N' Roses in 1985 on the Hell Tour met with raised eye-brows among his old bandmates. But while a number of Seattle bands appeared to be the antithesis of GN'R, Duff himself was a firm supporter of the plaid-clad types emerging from his hometown.
"I knew the guys who ran Sub Pop. I have 1,200 old singles and shit," he continues. "I was like the LA liaison for all the Seattle bands coming down. When Alice In Chains came to LA on their first record I played bass with them on Man In A Box. I was really excited by those bands. It was great to see Soundgarden and those guys doing well."
By 1991, as Guns N' Roses began to slide into self-indulgence and disarray, one band in particular emerged and represented the dawning of a new era.
"Because Nirvana were also on Geffen, I'd gotten an advance copy of Nevermind four months before it came out. I wore out the tape, you know," recalss Duff.
On April 2, 1994 McKagan would also find himself on a late night, homebound flight with Nirvana leader Kurt Cobain.
"I sat near Kurt on the plane and when we talked, I could tell something was wrong," states Duff. "My buddy Eddie met me at the airport. Kurt and Eddie were outside having a smoke while I was collecting my bag. I said to Eddie, Why don't we take him over to my house tonight? Kurt was just gonna go home by himself having snuck out of [LA rehab centre] Exodus. So Eddie went running back out to get him, but a car had to pick up Kurt. We didn't know what was gonna happen, but you could sense something wasn't right."
Three days later that sense of unease would turn to tragedy.