My AS son J is 10, I still have to sit with him in the bathroom. If I don't nothing gets done, he just sits there or he will play for hours and hours (if I let him) with his bath toys.
He has cups and bottles for pouring stuff, he has a little liquid soap in a pump bottle to make bubbles or do what ever with (face it some of that stuff is pretty to watch when your tipping it upside down and pouring it out, it also does cool stuff like make bubbles. Its all a little like a lava lamp) J also has bath flutes-I found them in the baby section (I would never tell him this) at our local supermarket. You fill each flute with water to a different level and it makes a different sound, they also came with water proof music sheets that stick to the tub walls. He has the standard soldiers, dinosaurs, lizards etc.
J doesnt wash himself unless I specifically go threw each and every body part with him.
Perhaps your daughter is trying to do the right thing, and use just a portion of the products but is having a hard time measuring this out and pouring it for herself. Perhaps she is accidently pouring too much and then trying to get rid of the left overs.-Just a thought.