A quick thought on Gdiapers

Gdiapers are touted as being better for the environment in drought stricken areas because they are flushable. Supposedly cloth diapers take way too much water because you have to wash them. I may be missing something here but- don't toilets take water to flush? If each time you change your baby's diaper you have to fluish the insert, isn't that using up something like 5 gallons per flush?

I'm not taking the time to do the complete math here, but something isn't adding up for me.