yep, I may have it backwards as to the construction, still doesn't change the fact that all RV hot water tanks don't have an anode rod.
ours still smells after filling it up after 2 or 3 days
the only way to keep it from smelling is to use a chemical. our water is not chlorinated. if I filled it from a city faucet I might not have this issue. if the last place anyone fills up is pumped from a well (lots of campgrounds) you can have the same issue. there is going to be bacteria in the water
in fact, every once in a while we have to crack the well head open and sanitize it. every time you work on a well and open the well head, you do the same.