How to get pass the quick sand in Pokemon white?

simple: you go around it

First get 48 battle points on battle subway. You get 3 points for every 7 battles. Then go out of the train.You will see to men go to the one on the right. Scroll downuntil you see quick claw.

its a wi-fi item till aprill 10th

While still on the title screen you select MYSTERY GIFT -> RECIEVE GIFT -> GET VIA NINTENDO WFC. It will download to your game and you will then be able to pick it up from a delivery man at any...

By a Wifi Event, but its already over.