[IL] Woohoo in the waterfall decreases hygiene/hydration need

One would think that, like woohoo in a shower, woohoo in the waterfall in Mua Pel'am (and other water based woohoo locations, such as hot tub and in the water) would increase hygiene (and hydration for mermaids.) Even if the water isn't sufficiently clean to increase hygiene, one would think that having water cascading around you would increase mermaid hydration, but apparently not, as my mermaid sims just woohooed in the waterfall and lost hydration while doing so.