Use sand not dust. Dust is not safe. You clean it whenever its necessary.
If the hamster pees in it you will have to change if more often. If you give him/her a small sand box you will have to clean it often. I rarely have to change my hammies sand baths.
You can make it as deep or as shallow as you want. It really doesn't matter. Some hamster like to dig in it so you can make it deeper.
If he/she just wants to roll around in it then it doesn't need to be deep.
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.