Sulfur salt blocks have generated a love/hate relationship among many cattlemen. Some love them and swear by them, then others feel they are a waste of money. It can be a bit of a headache to truly understand either side.
The ones that love them say that it helps with external parasite control. While putting sulfur powder has been shown to help in that area there is no, as far as I’m aware, evidence that the block does that.
As with everything there are pros and cons to using them. While there is some benefit to feeding sulfur one must also be careful. You need to weigh the options yourself and decide if it could be something that will work for you.