You know you can do that with surtling spawners too. I love to parry his attacks when he is standing over surtling spawner. He takes extra dmg from fire when he is staggered so he dies very fast. Im not sure, but i think upgraded bronze buckler combined with good foods can parry all of his attacks.
My strategy for swamp is to always flatten the ground around surtling spawners a little bit below the water level. Surtlings will die when spawned in water, and wont interrupt my fight with abom.