It would work. Basic meteorology explains it. But, what a waste of time and effort. It would be akin to filling you foam space with car wash sponges. Nice and dry ..... but extremely thirsty and over anxious for the first sip !
Brief hijack .....may have been posted before.
What would be the problem (if any) of sealing the flotation areas completely, leaving an inspection port of sorts to occasionally check for water intrusion ?
Similar to the preflight inspection of a seaplane. Or, the hollow, empty pontoons on a pontoon boat. The cavity(s) could be sealed as well as a fuel tank and checked / siphoned as needed .. if ever needed. Pay attention to the waterline as an indicator ? Flotation only needs to work for , how long ?
Till you're rescued ? towed in ? Hours, weeks ? It could even leak a little.
Just wondering.
Please excuse,
Thanks