CAUTION : use this machine on a new map first to practice. It is make for blocks erasing !!
You can watch a demo here : https://www.youtube.com/watch?v=fyZ96DrsnpM
I was bored to clean blocks while map-making. So I decided to create a cleaning machine. It uses armor stands to delete blocks around in different ways.
The machine is 7x4x13 and will appear on north of you. Once here, buttons are on the sides (both) to get the stands. You just have to place them for seeing blocks become air. There's a another command to put a 20x1x20 grass below.
Enjoy and please give me some feedbacks. It's my first OneCommand and there may be some bugs (hope not)