I haven't got enough experience, but I haven't seen my guy do this yet. I did say the first time I saw him deficate I was a grossed out by the process - had never seen a lizard passing anything before
I'm serious. I don't put him directly under the water. His back is ouching the water and his mouth opens. Its warm water, not hot. He literally shat once. I started to rinse him off and I was thinking, "wow, thats some sticky poo." i found out it wasn't poo.