We resisted using the bathroom for anything when we got our popup, but once the kids got older and we couldn't split them up for showers in the bathhouse we started using the shower and toilet. We have two girls - once my oldest started asking certain questions probably around age 3 it was time. It would have taken too long in the morning to have my wife take both. Staying in the popup was so much easier!
We leave our sewer hose hooked up and the gray tank valve open. Since the black tank will last for most of a week I'll wait until the day it needs to be dumped before closing the valve for the gray tank to fill it up with a few showers, then dump the black and then the gray, leaving the gray valve open again.