Are those navage nasal irrigation devices safe and effective? how do they compare to netty pots?

More automation: They compare to Netty pots the way electric toothbrushes compare to manual toothbrushes. Do you need the extra automation? Sometimes it can be helpful but most people can use a manual toothbrush and do not need an electric toothbrush. Same with Netty pot versus the Navage. I prefer the squeeze bottle over the Netty pot myself.

Safe/effective ?: As long as the directions are followed the unit is safe. You must define effective in how things work out for you. They suggest using warm water with their saline pods, but it can work without. If you can breathe through both sides easily a session can be done in a minute with visible evidence of the washed out material. The trauma of a automated flush may lead to more rather than less problems.