Ancient remedy

Dread to think what  the 'sell by' date would be on this.
It was given to me by an elderly friend who thought it would add to my green bottle collection.  Still has the contents intact.
Bought the floor tiles and a new light for the bathroom.  Plumber is coming tomorrow to fix a few bits and bobs.  Will not be complete until the half pedestal for the basin arrives at the beginning of March.  Was told last week that it 'is on the water'!