Seems you can only turned into an animal once hit by the Animalizer. Once splashed with water to be back to normal, the target has to be hit by the Animalizer in order to become an animal again. I could see the Animalizer being used by Nagato and Tenryuu for hijinks, but avoiding water is impossible.
i wonder how they got wet and ran back to admiral office in 20 sec?
So, don't be messing about with water, you hear?Why a pibhglhsgbahgh!With the Animaliser, you can turn your target into an animal!All it takes to turn them back is a splash of water!If you get turned back, then you need to come here right away - you got that?20 Seconds Later.I mean it! No splashing around along the way!If you want to turn into an animal once more, then you'll have to be shot by the Animaliser!