If only you could see Frederick have his bath. It happens exclusively during the vacuuming--I suspect he thinks the noise covers his bath sounds and keeps him safe.
Like the circus man who dives from a high platform into a tiny bucket, Frederick plunges down into the water cup from above.
To the extent he can, he throws water all over himself while keeping his feathers outstanding. He triples in size.
Water gets all over the floor, and I hardly need to add, it's funny.