Yes, dipping powders are sanitary. They do not provide an environment that bacteria can survive in. In order for bacteria to survive and spread it must be in a moist environment. The powder will not retain moisture in the jar and therefore does not create an unsanitary environment. Dipping system pots are completely safe to use, so no need to worry.
However, we recommend that the jar be used by only one person. If you want to share it with other people, we advise you to use a separate container.