The reason I have lagged it is as follows
On the Bailey there is some form of baffle at the drain valve which restricts / slows the flow from the waste tank ( plan to take off in the spring and replace) and when I was away in minus 2 even with the drain open and a bucket the waste pipe / drain valve still Froze !!!!
We never had a problem with our waste pipe freezing on the Autoquest but I agree about the ridiculous tap. When ours broke (as they inevitably do) I replaced it with a water butt tap which gave a much better flow.I remember our old Elddis had a ridiculous piece of 22mm hose with a tiny tap on the end. It took ages to drain the titchy 45 litre waste tank. I say drain, but it never really did, the exit hosetail wasn't even at the bottom of the tank!
I'm glad we haven't got it now, it would have frozen solid in no time at all once it got below freezing!
Hymer's too and of course the waste tank is in an insulted enclosure heated by the vans heating system.My Rapido has a much better design in that the waste pipe does not have any water in it until I open the drain tap. No water = no ice
Bailey you could do better.