During the Main Phase (Quick Effect): You can target up to 3 Spells/Traps in your GY; banish them, and if you do, shuffle them into the Deck during the End Phase of the next turn. During your Standby Phase: You can target 1 of your banished Spells/Traps; Set it. You can only use each effect of "Secret Stash Slipshod Squirrel" once per turn.