Biotex for whites

[filthiestfis]

I understand that Biotex is a washing powder used for whitening whites. It retails at around �1.99 per box.
Is there anything cheaper that works just as effectively as Biotex to whiten white clothes?

[O'Reilly]

vanish is pretty good - liquid or powder. I don't have skid marks up my boxers after washing them in Vanish (if that's of any help)

[pussnboots]

Soda Crystals, put half a cup in with your usual detergent and its as good as anything it only costs about 60p and a bag lasts for ages.

[weeal]

lol @ O'reilly