I own this scene and have seen it a few times. I always loved that little white outfit. White anything in mud is my favorite.
Kristine certainly did seem to enjoy her initiation to the world of mud and quicksand in this scene. In fact, I'd hazard a guess that she liked this quite a lot...she's still doing it!
Between the location (Chester, the site of some of the earliest quicksand videos ever made) and the actress herself, this scene is quicksand history.
Nessie