Swift - WatchKit: How to get data back to the root view controller?

Suppose I have three interface controllers which are all linked by push segues.

InterfaceController1 -pushSegue-> InterfaceController2 -pushSegue-> InterfaceController3

InterfaceController1 has table which will house the data from the class below.

So, suppose I have class:

class manageData {
    var data1:String?
    var data2:String? 
}

and this class is supposed to hold the data from InterfaceController2 and InterfaceController3.

So InterfaceController1 creates a manageData object and passes it to InterfaceController2 using the contextForSegueWIthIdentifier method. InterfaceController2 then adds to its data to the manageData object and passes it along to InterfaceController3 using the contextForSegueWIthIdentifier method as well.

Now my question is, once InterfaceController3 adds its data to the object, how do I pass that complete object back to InterfaceController1 with the data filled in so InterfaceController1 can add the data to the table? Hopefully I've made this clear enough. I don't have any actual code to represent this because I have no idea how to implement it yet.

So the way I solved this issue was to create a singleton class which held all my data throughout the different controllers. Then when I reach the last controller and send my data to the singleton, I pop back to the root controller.

When I'm back in the root controller, in the awake method, I call a function I made called loadTableData() which automatically takes information from the singleton when it awakes and loads it in the table. Seems to work perfectly for now but I don't know any potential issues that can come up with this method.