What Cucumber to Buy?

[Tigger]

I am looking for something to stir up the sand. I am thinking of buying a cucumber, but I heard that if they die, they give off a toxin that will kill all of your fish. Are their any cucumbers that don't do this? Which cucumbers do you recommend. J&L has both the Tiger Cucumber and the Black Knobby cucumber. Are these any good?

What are your experiences with cucumber.

Do you think I should just get nassarius snails instead?

Thanks