dont they need to breath through the water? If not this is probably the most cost effective approach
No, don't need to breathe through water. I prefer to ship them in damp paper towel too. I even snip off the corners of the bag so a tiny bit of fresh air can get in. There isn't enough water to be drippy and the holes aren't big enough to allow the paper towel to dry out. In the past I have used a padded envelope and 1st class mail but if it's hot... they may cook.