The interesting thing about the ionics system is that it will wreck the vans chassis although the crash will probably wreck the van anyway. I think one reason why a container needs to be secured is because the water moves within it even if it is baffled. So the force of stopping plus the force of water accelerating within the tank could cause an unsecured or poorly secured load to go through the bulkhead.
I think a better idea would be to have a tank that disintegrates when these kinds of forces are applied, at least then you won't have damaged your chassis and the van may be salvageable, the resulting spillage may even put out some flames.
I had heard of a lady driving to Glasgow who had a van loaded to the hilt with kitchen work tops, she came to an abrupt halt and a load went through the windscreen above her head, some also managed to fall out the back door as well.
Simon.