Break the Bears Head into manageable sized pieces so that you can inspect and clean it. If the mushroom is very clean, great, if it's dirty, dip it quickly into a sink or bowl of cold water, give it a firm "swish" then wrap it in a towel to dry and weep water.
Hericium can hold a lot of water which I like to cook out for the most firm, meaty cake possible. I sweat the mushrooms until they wilt to begin the cooking process, squeeze out the water, then chop the mushrooms, recombine with their juice and cook until the mushrooms are glazed in their liquid to not waste anything, but you can just squeeze the juice out of them and discard too. If your mushrooms were very clean and you didn't have to rinse them in water, you may not need to squeeze out much liquid at all after you've wilted them