A knotted necklace chain can seem impossible to undo, but with the right tools, you can slowly untangle it.
If your chain-style necklaces have somehow tied themselves into knots, this video from YouTuber CrazyRussianHacker demonstrates a super simple method of untangling them. You'll need something with a fine point and a lot of patience, but it can be done. Of course, it doesn't need to be a screwdriver as long as the point is small enough to wiggle it's way into the necklace's knots. Slowly but surely you'll undo them all. If the knots are really bad, you can try dabbing them with Windex and setting them on a washer or dryer.
How to Untangle/Unknot Gold Chains Easy [YouTube]