Sounds like the water has high iron content. All the chlorine does is mask the smell. Frankly I'd rather live with the smell than deal with the chlorine. I would suggest a 2 stage filter on the inlet to the RV. One stage a sacrificial particulate filter and the second stage a carbon filter. That should solve the problem. The carbon will remove the chlorine (provided it's actually chlorine and not chloramine - you need catalytic carbon for that).
Something like this:
2 stage filterIf you are drinking the water however, I would opt for an RO. Something small under the sink or a Burkey gravity fed RO.