Ok, here is the thing for anyone needs assistance.
I managed to log my users out using FBSDKLoginManager instance
Apparently and i don’t know if is it documented or not FBSDKLoginManager watches
FBSDKAccessToken.currentAccessToken()
so
let loginManager = FBSDKLoginManager()
loginManager.logOut() // this is an instance function
Logs the user out, what i misunderstood that logOut is not a class function.