wiring a light fixture with a two hots and two neutrals
Connect all the (colored) hot wires together. Connect all the (white) neutral wires together.
The white neutral wire out of a light fixture must be connected to neutral. The black hot wire out of a light fixture must be connected to hot and a white wire (such as coming from a switch) may not be used for this connection.
When cleaning anything including baby diapers, it is better to sweep off or scrape off as much solid and semisolid material as you can first. (1) Less cleaning fluid or detergent needs to be used, (2) Less of a mushy mess which in turn means that bleaches or disinfectants will be more effective.