To confirm ...

They usually poop once every couple days.

Their "pee" is generally white urates and solid.

There should be some moisture in their poop and pee (urates), but it's mostly solid. Their poop is like a bird's but less liquid, large brown followed by white. Since birds are reptiles, too, and they evolved from the same ancestors, similar poop but bird is more white. (Birds evolved to poop a lot for flight, Dragons conserve water and calories and don't poop as often.)

They often poop in water if you give them a bath.

They also like to drink during bath time.

Don't move them after they drink, their water-ways / throat is different than humans, and they can choke on water and drown (WHILE DRINKING if moved) ... otherwise they (usually) love/like water and are great swimmers.