I purchased the Simple Shower off of Amazon a few weeks ago and have taken roughly a dozen showers with it at home. I have short hair and have found that I can bathe and completely rinse off using two liters of water.
The threads are compatible with my Evernew bladder but I haven't tried it with a Platypus bladder yet. If anyone is interested, I can try to dig one up later and see how it fits.
It weighs less than an ounce and only set me back $13. I've drilled holes into water bottle caps before but I much prefer this system.
Here's the Amazon link:


