We've been in our caravan for 4 months and do most of our cooking and washing up in the van as we are on C.L. sites. We have noticed that the water pipes are smelling now, (no huge surprise) and have used milton to 'soak' them in over night and blocking off the outlet with clingfilm and a rubber band, the smell wen for a day or 2 but is now back! Help...what else can we do?