have soaked the mussels in water, and changed the water several time.
but somehow the water still looked dirty.

are the mussels still edible after being soaked in water for so long?

haiz....should hv bought the cooked one......

Just google "how to clean mussels".
You will find steps, instructions, videos!

Actually I would be curious how the "cooked" ones were prepared. Did they clean them as much as we did or is it a matter of "out of sight, out of mind"?

Use the brush to brush like brushing your teeth.

Soak in water with few spoons of flour. Flour will make the shell cough out the sand. I vaguely remember something like this when I watched Food Network Asia few months ago. Pls google first before u do it. Don't me if wrong.

Soak the mussels in salt water for a while. That should make the mussels cough out the sand. Change water to get rid of all the debris. Wash again then brush/scrub away the barnacles on the shells. Make sure you throw away all the dead mussels /mussels that are broken. Only cook/eat those that are fresh.

Enjoy.
p/s: with waters being so polluted these days, not a good idea to eat them often