I bought a cheap version a couple of years ago. It works well for me. I like to take a shower if I can. If you are worried about bacteria growing in your shower don't. What about your canteen. I grew up camping, was in the Army, and am outdoors to this day a lot and I have never had a problem with bacteria growth in a water carrier, just use common sense. If you are worried put in Iodine or chlorine pills. That will kill virus or bacteria. I always carry water purification pills with me as a backup.
"The older I get the better I was"