When I was a child in the late 1940s, Britain’s postwar economy was still in poor shape and luxuries were few. The toothpaste we used as children was not a paste at all, since there were no plastic tubes and such toothpaste as there was came in flexible lead tubes which you squeezed. The paint would peel off the tube to reveal the grey lead underneath. With Britain trying to recover from the destruction and shortages of a world war, lead was needed elsewhere and toothpaste was expensive. I can't imagine the lead was terribly healthy.
Instead we used Gibbs Dentifice. It came in a round tin with a dome-like tin cover, and looked like a cylindrical cake of pink soap sitting on the base. You had to brush a wet toothbrush across it a few times to whip up a foam, rather as men did with shaving cream. With this somewhat gritty pink foam you cleaned your teeth.
I must have used it thousands of times as a child. It cost about 7.5d in the old money, or about 3p for a tin. It had flavour added, a sweet, slightly soapy, slightly sickly taste to it, and it was pink. The nearest flavour that matches my memory of it is that of Pepto-bismol, the anti-nausea medication. The fun came as each block neared its end, and I would scrub the tin carefully, and see how long I could make the remnants last. I suppose I switched to toothpaste in the early 1950s, maybe to Gibbs SR, but the pink block in the tin is now long gone.