Maybe flush the pipes through with something like puriclean or Milton? Thats what we use to flush ours through every so often. Might get rid of the taint in the pipes? And tbh we don't ever use the water in the van for anything other than boiling for tea/coffee or for cooking. We buy bottled water f...
We used to take our dog away with us all the time in our old campervan and we just used to bring his dog bed from home and wherever we put it thats where he slept
And I think keeping dogs on a leash at campsites is only fair for us folk with little'uns running around