Recently Facebook had decided to make messenger access able without facebook account. Yes after this you can use facebook messenger as a push messenger by registering your no. in messenger to access it. You can see the complete process to setup this in the below steps.
1. First of all download and install Facebook messenger app in your smartphone.
2.Now while singup click on Not on Facebook? there.
3. Now you will see page asking your for details fill us little bit details like first name, last name and phone number and you are done.
4. Now your account will be created with lots of friends that using messenger in similar way.
5. As from this now you will be using messenger without any link to any personal account with the limited friends as here you will a push message messenger with lots of friends that you might even not know.
You can make unkonow friends here who all are all using facebook messenger by this method on messenger.