There's no real strategy for this achievement
There are five traps in Shi No Numa, The Fogger, which is a giant spike machine located above the entrance to The Fishing Hut, and an electric trap at the door of every Hut (Where the perk machines generate)
Knowing this, you need to save a lot of money, this also requires luck. What I did was (This was around round 12) I started and went into the Fishing Hut side of the level, and activated the Fogger, after activating it, I ran to the Fishing Hut (By this time zombies have spawned from the water) and flipped the electric trap, after the trap wore off, I bolted to the Doctor's Hut and flipped the electric trap there, killing zombies and unlocking the achievement.
Please note, that it does not matter what order of huts you go to, as long as you kill at least one zombie with three traps in one round.
Good luck!