Replace all glass around player with air, then undo

[GamingGeek]

I'm trying to replace all the glass in a certain radius around a loop-player to air so they get released from the cage, then undo it so the glass is back for when they respawn in the cage. I've only been able to get it to replace the blocks one by one...
IMAGE:

This is what I have....

                loop blocks in radius 10 around loop-player:
                    if loop-block is glass:
                        set loop-blocks to air
                        wait 2 seconds
                        set loop-blocks to glass

 

[TPGamesNL]

                loop blocks in radius 10 around loop-player:
                    loop-block is glass
                    add loop-block to {_list::*}
                loop {_list::*}:
                    set loop-value to air
                wait 2 seconds
                loop {_list::*}:
                    set loop-value to glass