As a follow up to this thread.
I filled the fresh water tank and added 2 cups of bleach and ran it thru all the lines and let it sit. Flushed it out and did it again. Flushed it like crazy and so far, so good. The smell seems to be gone.
This also served a dual purpose in that this is the first time I've ever used the fresh water tank so it's now been bleached/cleaned and ready for when I go dry camping and I know the water pump and everything works.
Thanks again for all the replies!