Have nothing to add really, but just for the sake of spamming, here is a quick shower advice: If you dont live alone - check the bottles before "borrowing" someone's shampoo
My favorite Fructis shampoo ran dry, so i took one of many bottles my wife is using - turned out to be a body-cream-scrub-whatever. DIdn't form any foam, and made my hair all oily and thick...
Tbh, I have been doing it for a while now, i keep forgetting to buy that stupid shampoo for a couple of weeks, so i just take a little from every bottle we have in the bathroom