Answer:
Sand
Step-by-step explanation:
If you get salt or sugar in your water, you have to legit desalinate it to get the water and item out. You need to evaporate the water by increasing temperature and then lower temperature to separate the substances.
If you have alcohol, you need to distill it by trapping it and stuff.
With sand, the molecules are much larger which lets you separate the substances easily.
For example, on a beach, you can slap a handful of sand in your pail, but the sand sinks to the bottom right? You can just pour out the water.