Definitely rinse it. I was very glad i did, you wouldn't believe the stuff that came out! It even had some weird colored plastic thread bits and other random stuff. After rinsing though all the sand settles really well with minimal/no dust storms.
I added mine the same way @Schnizzle did and didn't have any issues fwiw
I added mine the same way @Schnizzle did and didn't have any issues fwiw