I'm thinking it was Get In The Ring that they worked on... I seem to remember reading that Axl mentioned it at some show in the summer of 1991.
Correct Jarmo!
Got this from
www.gnrontour.com, check out the notes:
06.10.91 - Performing Arts Center, Saratoga Springs, NY
opening act: Skid Row
set: Nightrain, Mr. Brownstone, Double Talkin' Jive, Dust N' Bones, Bad Obsession, It's So Easy, Dead Horse, Civil War, Welcome To The Jungle, 14 Years, I Was Only Joking [Intro] / Patience, My Michelle, November Rain, Drum Solo, Guitar Solo, Godfather Theme, Rocket Queen, Only Women Bleed [Intro] / Knockin' On Heaven's Door, Bad Time [Intro] / Sweet Child O' Mine
encore 1: Live And Let Die, Estranged
encore 2: Yesterdays, Paradise City
notes: Special guest performance by Sebastian Bach. Axl announces that it is a "very sad day" because Poison broke up that day. Rare performance of Dead Horse during the summer '91 leg of the UYI tour. Axl leads the crowd in a "Get In The Ring" chant that is recorded and used on the song. He also says that they finished recording the song the night before in Toronto.