We have a rule at our house that the toilet lid goes down (why else would they have them if they are not meant to be used?). I always try to clean toilets without little, pretrained kids around. So I've never had a problem with little splashers.
This morning as Mason was getting dressed Emma was in the bathroom with him. I was in the kitchen & heard him yelling for me. When I got to the bathroom there was Emma splashing in the yellow water having a great time. Mason was not sure what to do. I was just grossed out. What a great way to start Halloween!