For the wood piece in your tank, I would put it in the sink, wash it with some Dawn dish soap and some bleach, and rinse well. You can also put it in the oven at 300F for an hour or more, depending on how thick it is.
Romain is only an ok veggie, and Iceberg shouldn't be fed as is has no nutritional value. Collard Greens, Dandelion Greens and Mustard greens are much better staple veggies. I know that our Walmart sells Collard and Dandelion greens regularly and they are cheap, $2 a bunch in my city.
If you dragon is still young, you should be feeding him mostly insects. Juvenile dragons should be eating 50-100 crickets a day and a small amount of veggies can be offered as well. Once dragons are adults, then you will increase their veggie portions and decrease the amount of buggies that they eat.
Why are you
bathing your dragon every day? How long has this been going on for?