Detergent for ‘hand wash only’

I am always in two minds what detergent to use to wash ‘hand wash only’ cloth. In Denmark I would purchase a package of soap flakes and dissolve a handful in warm water to wash the item; but time has moved on and I am not in Denmark, and I don’t know if soap flakes are available in UK. I found out they are in all supermarkets.
But anyway; I came across this handy, always available tip of using shampoo instead of the soap flakes. I tried it on one of my scarfs. It was easy and it worked.