Fish recommendation to clean sand?

[twiddle]

I am wonderng what a good fish would be that would clean my sandbed without digging under my rock and corals.
I have a 72 gallon and a 9 gallon nano and would like a recommendation for both tanks. The nano would just have another clown fish.
Thanks!

 

[BLKTANG]

Bullet goby.

 

[birdy607]

well its not a fish. I would try a coch i purchased one about two days ago and did i ever see a difernce in how white my sand was...