I forgot to add this comment about Geckos. I loved them. When I lived in the Middle East they were in my house and would climb the walls and ceiling in defiance of gravity. They were bug eating machines. They were my friends. I had about 3 or 4 that lived in my house. I feed them nothing as they ate the bugs. I did leave water out for them.
In the article I read about this, the only the issue the writer had was being disturbed by the occasional sound of chewing in the dead of night. (That, and he would find the gecko in the most unusual places on his walls or ceilings.)
Like you, he always left water out for it.
But they poop all over the place.