All of these things pick up energy. Metals will buffer the energy until they're full and then they will reverse and send the energy back out. The same is true for people who wear a leather belt for years. Leather is organic and picks up energy. I teach a simple method to clean leather belts and other leather items.
Leather is easy to clear.
To make sure you do not take any of the energy you're clearing from the leather into your body, place a rubber band just below your elbow on your clearing hand. For men, your clearing hand is usually your right hand, and for women it's usually your left. The rubber band is used to remind you to pull the energy only up to the top of your forearm. Hold the belt buckle with one hand and grasp the belt with your clearing hand. While aware of your intention to clear, pull the built-up energy out of the leather by pulling your clearing hand along the entire length of the belt five to ten times.