Ah yes, Gregg "The Freak" Valentino. Very interesting character.
Yes, his steroid usage has helped him develop 24" arms, however he claims to have had 21" arms when he was natural. And at the height of his gear usage, 27" arms.
You can read an interview with him at
www.bodybuilding.com ...it's quite interesting. He is a very unorthadox person. There's a few tidbits in the bodybuilding.com article that weren't included in the t-mag interview, especially some amusing antecdotes about his former nutritional supplements.