I gave Juju a bath today and he did things I've seen other people post, but i don't know why.
for one, he used his front and back legs to 'scratch' at himself, or was it to put water over his body?
He also poo'd, but i knew that could happen (tho it never did before)
and he also ran at a corner, and then swam at it (while being against the wall of the corner)
I made sure the water was the right temp and height...
All of those things are perfectly normal. Is your beardie shedding? If so, then the scratching may be an attempt to remove loose shed. Pooing in the bath is perfectly normal and if you're lucky like I am, eventually your dragon will only go in the bath and you won't ever have to clean it out of his enclosure ever again. As far as the running and swimming towards the corner, probably just testing boundaries looking for a way out.
The water should come up no higher than their "armpits". Any higher and they will feel insecure and puff up to float. They should be able to touch the bottom of whatever they are bathing in. At minimum their vents should be submersed in the water as they take water in through them and this is how they hydrate themselves.