(Need Help) In Skript how would I make it so placed blocks in a certain region vanish after a set amount of time?

[FireClawInfinity]

I'm very new to Skript, and I am trying to make it so that after a certain amount of time the placed block vanishes, not like all blocks at the same time, but only player placed blocks. I'm trying to make a pvp area in my server, but don't know how to set it up correctly. Any help is appreciated, thanks!

[Agecy]

Hey boss
I would add all the blocks to a list variable (when they are placed).
Then I would make a loop for the amount of time. Then set the blocks to air.
 

on place:
	add location of event-block to {blocks::*}

every 10 seconds:
	loop {blocks::*}:
		set block at location of loop-value to air

Haven't tested but I'm pretty sure this should work.