i dont have an iguana but i do have a bearded dragon which you do give them bathes as well..and what i do is run a warm bath that goes up to her tummy a little deeper because she likes to dunk her head and swim under the water..very graceful i might add..but just make it warm for them...our water has a filter that takes out the chlorine but i dont think the water will be too harmful only because some people drink water straight from the tap.