Sundance 530 lp

My Daughter and her partner have purchased a 2010 plate Sundance and I have noticed that there isn't a fresh water filling point for the toilet.The salesman said that the water for the toilet flush comes direct from the on board freshwater tank.If this is true,then how do you add the Pink chemical to the flush system? When questioned about draining the fresh water toilet tank the salesman said that it is drained via the water heater.The toilet is a CWE 250 so is this information correct.I have a Swift Conquerour with a proper external filling facility and drain pipes with the bungs in so all the above seems strange to me.Any information would be most welcome.

Thank you