Ok I am going by memory but I know this works. Erikas perfume allows you to look at your opponents had and put a basic on there bench if you have room. Not to usefull huh.

Well try this. Your opponent has a pesky unown D or some other unown on the bench you sneak attack and find out he/she has an unown in there hand. If you read the poke power on unown you will find out that more than one unown cancels another for example two unown D's cancel each other and tyranitar can hurt the bench again. So now that you know the have one use erikas perfume to put the second unown on the bench and your back in Biz. Hope it helps some