Added the scans for the Curve Magazine - April 2010 Issue with the Bitch Slap stars: Erin Cummings, America Olivo and Julia Voth on the cover.
There is a mention of Lucy in the article:
...She also received some tips from lezzie favorites, Lucy Lawless and Renee O'Connor, who reunited for a cameo in the film.
"Lucy was giving me some really funny ideas," Olivo recalls. "We just goofed with it, and played with it, and had a really good time."