You might be surprised to learn that cocoa butter, while derived from the same plant as chocolate, is generally safe for dogs when used on their skin.
It contains trace amounts of theobromine, the toxic compound in chocolate, but it's unlikely to harm your dog if they lick a small amount off their fur.
Cocoa butter is often included in dog-specific balms and conditioners to soften their skin and coat and promote healing for irritated areas.
However, it's best to stick with products formulated for dogs, as human products may contain ingredients that are harmful to them.