Not really much here, but there's a clip of Sasha Grey talking about her feet. Near the end, she licks on her own toes. The very end of the clip, the camera man asks if that feels good and she says "yeah...it tickles". Like I said, not much...but she did say it tickled her foot.
http://www.youtube.com/watch?v=cpJfujR7d1c
http://www.youtube.com/watch?v=cpJfujR7d1c