No this is not some strange formula designed to catch fish , in fact I believe that the opposite it true. When I started fishing an old man told me never to bring an orange to eat when going fishing, never to put suncream on before fishing and most importantly never to fill up the car with petrol/diesel before fishing! He always advised washing your in the mud and water of the venue before putting on any flies or bait?

Is this true, do fish - and I'm talking trout and grayling here - actually react to smells?

I know in the US the bass fishermen there use sprays and the like, does any put any smells on their flies?