i've been useing the canvas bag type shower for yrs, there great, i havent had much luck with the solar ones, they go mouldy on me when not in use, pretty hard to dry em out with only the small filler hole, & you realy need one per person, i can have upto a doz people for a weekend.
This is my latest, it's a few yrs old now, often newbies would turn the canvas bag rose off to tight & i'd have to pull it apart to sort it, also they would always worry how much water was left.
So i made this out of an old catering food bucket, it has a toilet systern tap, mainly because it was the lightest (easiest to turn) tap i could find, a couple of plastic fittings, i made it all up in the aisles, of bunnings

, then used an old shower fitting from home, just removed the long shaft.


I timed my bag shower & it went for about 3-4 min.
Inside the bucket i screwed a plastic blank into the pipe fitting blocking it off, then started by drilleng a 3 mm hole, then 4 mm etc till it ran the same time as the bag shower.
Next problem was there wasnt enough water to run the whole rose properly, so i cut a circle of rubber at about 40mm dia, & syliconed it to the centre of th rose, that only left about 4 rows of holes around the outside, it run nice then.
Works great, you get about 4 min, you can always see how much water is left, i usualy get wet turn it off then soap & shampoo up

then turn it on to rince off .
we heat the water up in an old keg when there are a few of us, if it's just me a fill an old staino ern in the morning & just leave it in the sun all day in summer, just boil a kettle on the gas in winter.

Trev
Aus