[jake]

a good tip for cleaning laces if putting them through the wash isn't working...

using hot water and washing liquid(ariel, etc) in a sink, dip the laces in the water and with a scouring pad, scrub away at the laces concentrating on small sections at a time. Obviously this will need to be repeated for both sides of the lace but if you've done it right, they will look brand new. Once cleaned, rinse them out with cold water and allow to dry.

Edit: Just to add, use the base of the sink to press the laces against whilst scrubbing, holding them in your hand and scrubbing wont work as well.