Krakatoa Foam

Some of you will remember from your youth a substance called Creamola Foam. This was a drink concocted from a spoonful of rather sweet flavoured powder mixed with water. The reaction between the two caused much frothing and bubbling until the drink emerged with a layer of foam on the top. Lemon and orange I seem to recall were the favourite flavours.
The drink seems to have been resurrected under the name"Krakatoa Foam"and is being promoted on a stand in the Thistle shopping Centre. It seems to me to be pretty expensive at £3.99 a tin!