In view of the recently raised interest in the nasal excavation digital activities of a certain (unelected by the English) Tartan Tax Thief, I feel it my duty to point out to those who may not know, the difference between an iggle and a bogey!
It is simple to tell the difference, although I should point out that the testing method is potentially destructive. First, as Mrs Beaton would say, catch your specimen by inserting your index finger of the appropriate hand into the appropriate nostril. Have a good dig about and get a suitable deposit on the end of your finger. Extract your digit with specimen suitably placed on the fingernail. Now, with a deft movement of your index finger, flick the specimen at the ceiling. If it sticks to the ceiling it is an iggle and if it bounces back at you, it is a bogey. Simple, isn't it?