I too have a composting head question. Has anyone had small children use them? Are there extra challenges?
Our boat has abysmal raw water tankage, and no way to add more. We are strongly considering switching one of our two heads to a composting system before we move aboard full time for a year.
Our two boys will be 5 and 3 when we move aboard next spring.
What are they moving from? NH are far easier to use than a manual marine head (but not as easy as a single button electric head)
They may need a step.
Use: sit on it, if you are planning a #2 you open the trap door, you do what you need to, you close the trap door. No worries if #1 *and* #2, it directs everything like magic. When they ask about the crank, introduce it.
The challenge to their acceptance will be on your end, not the childrens' end. They are at the age where they absorb information like little sponges. As Captain Jack Sparrow said, "The problem is not the problem. The problem is your attitude about the problem." If they hear you talking, "I hope the little one can learn how" ...If you stress the kids about a new toilet that they "will have to learn" they will be in the wrong frame of mind when lesson time comes. They will fear the device before they see it.
Don't talk about it, don't worry about it. When you install it, if they ask why, tell them it makes it easier to be away from the pump out. They will probably think that is a good idea.Then, "Oh, here's how you use it. Better than all that pumping with the old toilet, right? Mommy and I will be happy to help you. OK, give me a hug and go play."