This "trick" is not actual cheating/hacking, but rather a way of using the skin equipment screen from the store. I personally do not agree with the use of hacks and cheats in this game, because while "getting good" is harder, it yields superior results.

1. Start a match and pick your standard shark/weapon skin.
2. At any given point in the match, enter the store menu.
3. Enter the skins section for your class, (Be it your diver, shark, or weapon), and click a different skin from your current one. You must own it in order to be able to equip it.
4. Click the "Equip" button. Once you respawn, the store menu selection will override the pre-match one and you´ll be able to switch skins to your heart´s content.