Easiest way to get fresh water between the liner is under the galley sink. When I drain my hot 6 gallon water heater every winter I run it dry through the sink, but still have some in the tank (maybe 3/4 gallon) so I remove the drain plug and let it flow to the bilge. Then I head out for a few hours and enjoy the sail. By the time I get back the water has found the way to the bilge, the space between the liner and hull is somewhat cleaned out, and I remove all the water and keep a dry bilge.