One of the best things you can do is let your iguana soak in a luke-warm bath. Depending how much your iguana enjoys the tub, you can leave them in there for around 30 minutes with supervision. Make sure the water stays warm because the iguana's body temperature will be that of the water. You can rinse your iguana off and gently clean its body to remove any loose skin, dried food, or fecal matter. Note, however, that your iguana may deficate in the tub as water has that affect on iguanas. In that case: remove the iguana, remove the feces, drain the tub, fill tub with hot bleach water and let sit for at least 20 minutes. After that, rinse tub completely, refill, and place iguana back into tub (if desired).