I reccomend the Himalayan salt licks rather than the flavored and processed ones.
If you horse chews on the processed ones, they can chew hunks off...resulting in quick destruction of the salt lick and possibly salt/mineral overdose. The Himalayan licks are completely natural, no flavorings, and they are literally as hard as rocks. They CANNOT BE CHEWED, ONLY LICKED. Beau licks his once in a while, but as an avid wood chewer, he has failed in his attempts to chew hunks off. Epona ADORES hers!!! She licks it several times a day when the weather is warm and she is sweaty.
Epona is picky, and I didnt think she would like it, but she does. She refused to touch the flavored ones. Beau bit the flavored ones into pieces just for fun..... he'd saturate it with mouthfuls of water until it was softer, then tear hunks off. He's weird, but wickedly smart.