I quit Facebook but was forced to return when it was the only way to communicate with certain Social groups. So now I use one of my old phones with nothing on

I quit Facebook but was forced to return when it was the only way to communicate with certain Social groups. So now I use one of my old phones with nothing on it, including no contacts, just for Facebook on a guest wifi channel on home router so it cannot link into main home network. I look at once a week at most. Otherwise it sits there marooned ha ha