I would use psyllium husk and spirulina

Psyllium husk, or just any other fiber will help it out. Raw veggies (especially carrots, with the carotene would help). Psyllium husk must be taken with LOADS of water, and 1 hour away from meals on either side.

Spirulina is great to helps toxic material out. I would go for both of these. Not together, at least one hour apart.

Jhan

Aswell as the fibre idea that Jhan suggested, you could try upping your zinc intake. I've read that zinc (and calcium actually) deficiency contributes to aluminium absorption. Also aluminium is absorbed more within an acidic environment (hence the advice to avoid cooking acidic fruits in aluminium pots). So maybe alkalise your diet....ie plenty of veggies.
(NB zinc and calcium help control acid/alkaline balance)

Anne