Ok, this thread is making me PSML. Here is my favourite from my medicine cabinet :
Warning, may cause constipation on an anti-diarrhoea medicine...
And some blinders from the DC's toy instructions :
Beware clothing involvement on a badly translated set of instructions that i think was translated from Japanese from a toy RC car.
Do not point into the sky on a children's telescope.
Be wary of accident in non-light on the instructions of a glow in the dark toy.
And, of course, contains milk on a 4-Pinter of, well, milk.
I get the need for a warning of allergens, having a DC with a dairy allergy, but even a fool like me knows that milk will contain MILK.