What to use to stir my sand?

[OCDP]

I put an order in for a black knobby cucumber.. but now that I think of it.. I really don't know anything about them..

So is there anything I should know about these creatures, or can you suggest something better that would stir my sand and keep it clean? I need to know by Sunday evening (or have made a decision by then)

It's oging in a 20g for a couple months max.. then into a 45g , so tank size shouldn't matter, would it?

[McNasty]

Black Knobies grow rather large, but seem to be the best for cleaning sand and hardeness, they do well in the aquarium, I have been trying to find one for some time now and as of yet I have not.

[OCDP]

I'm ordering mine through J&L on a clean-up crew order. So this would be a good choice? It won't get too big for a 45g?

[Johnny Reefer]

http://saltaquarium.about.com/blcucumberfam_stichopodiae.htm

[Invigor]

I've got one, as per quinster's recommendation. He works hard, but not hard enough, so i've got him teamed up with a sand sifting star and a banded goby and a bunch of snails..he's about 7" long now. Got him from J&L a few months ago.