A strategy that can be applied to all three of them is the use of Dung Pies. Make a run for the elevator shortcut and reload the area; they will be visible from the elevator exit and will not trigger from this position unless damaged by a weapon. Since Dung Pies inflict Toxic build-up but don't cause physical damage, they can be thrown without triggering them. They can quickly be killed afterward with a Throwing Knife once their health has been depleted.
Onikiri and Ubadachi