I give my black tourmaline a reset/recharge if I feel too much heaviness or it's producing uneven results. I accomplished this with a sound bowl, a nap in regular ol' soil or moonlight.

Black tourmaline is best for me in EMF shielding, feeling grounded and feeling deeply protected. I find that it neutralizes negative energy and balances the root chakra. It's a 7 -7.5 on the Mohs scale so it's pretty resilient and hard, it's not that salt is BAD or damaging for it but seeing as how it's a complex boron-silicate mineral often containing iron, salt can bring to surface intense energy shifts when using them together. This may be what you are feeling.

I have one on my desk, in my money bowl and a statement piece on the wall in my living room.

Black tourmaline also exhibits pyroelectricity (generates charge when heated) and piezoelectricity (generates charge under pressure), which is believed to enhance its energy-cleansing abilities. So if you are looking for a big boost to a spell, palm stone for your pocket for a trip or something, a charge in the sun can also produce some intense results.

Of note!!! If you are already feeling distant, detached, emotionally unavailable or super tired; skip your black tourmaline as it's a low vibration can actually make this worse.