The mm waterproof pump pack is a waste of money.
Try the aquapac. It's soft and you can push buttons right through it. It's kind of floppy but you can use a different belt or put the whole thing in a fanny pack. If just dirt is the broblem, there's Glad Press and Seal Wrap. I doubt it would keep water out if submersed but it should keep it clean.
DD age 12, dx at 4 (Oct 2006), MM Jul 2009, Guardian Feb 2010, Omnipod Jul 2012, Dex Jan 2013,
Dex/Cloud Jul 2014. Also peanut allergic and asthmatic.
DS age 14, non-D, but peanut allergic and asthamtic too. Also Asperger's, ADHD, and a pinch of OCD.