The kitty-litter isn't for the moisture in the hulls, it's for the condsation on the underside of the sheds roof ..... This drips down off of the purlins and the onto the boat ... Wrong drip in the right place could get past the hatch cover and over time cause issues .....
Cheap insurance in my book

That reminds me of one we've all forgotten ......
Contact your insurance company and give them the details of the storage time / location /etc
