Not true i am afraid.
myself and a bunch of other guys recently did a trip to Dieppe in France and we went via the tunnel but there was no lashing the bike down. But it is not needed anyways as you are stood next to the bike, and of course there are no rough seas to cross so the jouney is very smooth.
Halfords do an own brand and i have used it with great resultys on goggles while riding off road. It is a water repleant/mist inhibitor. It was around a fiver and because you only need a very small amount of it, i have had mine for e 2 years now. I think that qualifies as cheap