The Zotofoam bath
The Zotofoam bath was a precursor (from as long ago as the 1930s) of the whirlpools which are now so popular in health spas. It was once delightfully described as being like a Jacuzzi™ on steroids!
Unlike the Jacuzzi™ or other modern hot tub whirlpools, Zotofoam was designed to be used in an ordinary slipper bath. Bubbles were produced by pumping oxygen or compressed air through a distributor placed on the bottom of the bath. This was covered by hot water at around 105ºF to which had been added an ounce of Zotofoam extract.
The foam insulated the body preventing the heat from escaping and the body temperature increased so that the bather sweated profusely.
In Waters of health and happiness, it is suggested (in a phrase which could not be used today) that the Zotofoam bath 'through its special composition is unrivalled for slimming.' It survived until well into the 1960s.
Typical 1930s advertisement for Zotofoam
A Zotofoam unit at Epsom…
… and a bath at Hastings