"You didn't bring goggles?" John prompts mildly, and gives Ianto a moment to turn over that question before shooting him a sideways glance and shrugging. "If I stun them as soon as we see them they can't spit anything. If you wrap the things snout shut it can't open its mouth to spit anything if it happens to wake up."

So, it's all simple! Nothing to worry about. Probably nothing to worry about, anyway.