How to clear out this area fast in minecraft (Xbox360)?

I'm trying to build an underground city and it is taking forever to clear out this room because it is so humongous. The dimensions are 183x103x21 LxWxH. It has taken me days just to clear out part of one corner I need help

Guest

Use TNT

Jorge

Use potion of swiftness. Thats what i personally use it makes you faster. Also get a modded controller for lke 30 bucks which helps you clear out things extremely effeciently

Youssef Metwaly