Growing up in the fifties/sixties, Dettol baths were fairly common-place where I lived (Yorkshire). We had a metal bath in front of the fire once a week. ONCE a week, can you imagine that now? No indoor bathroom, no shower, just a good old tin bath. One lot of water bathed all 4 of us children in turn, oldest to youngest. Damn, I HATED being the youngest child!
But yes, there was a capful of Dettol in there. I remember how it made the water milky.
Although by the time I got my bath, there were more worrying things lurking in the water.
Kids these days, you don't know you're born!
PS Needless to say, I have never bought a bottle of Dettol in my adult life, because I just couldn't.