To waterproof I just basically do what mike does, bag the rx and box and a good blast of spray.I also put a bottle over the filter if there is a lot of standing water.
Results are here http://www.brca.org/?q=sections/subsections/pages/brca-lsor-2011-results/11577
Results are here http://www.brca.org/?q=sections/subsections/pages/brca-lsor-2011-results/11577