was relatively new to the Australian market in the early 1960's. I don't remember when I first saw the ads but I think it would have been 1963, maybe 1964.
One Sunday morning my step father awoke with a stomach upset. I'm certain it wasn't a hangover - I only ever knew him to drink at Christmas time and then it was maybe one beer with the boys or perhaps a gin and tonic.
So he, influenced by recent new ads for a wonder cure, despatched me to the local chemists to buy a bottle of Alka Seltzer tablets. Off I rushed. Came back with a bottle. He tore the seal off and unscrewed the cap. Took the first thing beneath the cap and dropped it into a glass of water. It stubbornly floated and refused to effervesce as seen in the ads. It took maybe 10 minutes for him to realise that what he was trying to dissolve was the polystrene filler between the tablets and the bottle cap!
I have to admit I was so ungraceful as to laugh uproariously!