My DD was a bugger for brushing, so one morning when she was adament that she wasn't going to do it (she was about 2.6) i said fine, took her brush of her, took hold of her hand (without saying a word) and went downstairs and got a plastic carrier bag out of the cupboard, by this point she was asking what we were doing so i told her "as you wont brush your teeth, you can no longer have any crisp/toffees/sweets etc" - (all the things she likes) I asked her to hold out the bag and i proceeded to fill it with all the goodies, she went hysterical, crying, trying to stop me, i explained AGAIN that as she wont brush, she can't have them....i then tied the bag up (securely) and got her to put it in the BIG BIN Outside for the dustbin men - this was when it hit home that they were really all going in the bin and she was crying and said that she would brush her teeth. We took them out of the bin and moved the carrier bag into the kitchen, where i told her "once she has cleaned her teeth, we would then put everything back".
It did the trick, sometimes i had to remind her that they would go in the bin, i only had to say when she questioned it, "what happenen last time, did mummy go through with it?" and as her answer would be yes, she knew
My DH asked what would i have done had she not had a change of heart after throwing them away.......i said that was why they were so well wrapped up, i would always have taken them back out of the bin but i did believed she wouldn't have let them be thrown.
I have a DS now (7) who knows this story and as DD has said mum means it, we've never had a problem! :)
If only ALL things in life was this simple :)