Went into my local ASDA and they have some Colgate whitening products for 3 for £3.
The best deal was the Colgate Plax Whitening mouthwash which is normally £3.40 per bottle, so it's better than buy 1 get 2 free.
Off the top of my head the following were included in the offer;
Colgate Plax Whitening Mouthwash; £3.40 each
Colgate Advanved whitening; £2.40 each
Colgate Deep Clean Whitening? £2.40 each;
Colgate Totoal Whitening Toothbrush.