M_at_oTo clean the system you want to add a cap full of bleach to the dirty bag, let it sit for an hour and then let it run through the filter. Then do the same to the bottom bag. This will sanitize the filter for long term storage.
M_at_oOne can store bags and hoses, but definitely not filters, in the freezer. This is an easy way to keep mold or mildew from growing in them. (Water expands when it freezes, which could damage filters.)