I think alcohol, carb cleaner, or acetone will throughly degrease it. Only other suggestion is to leave it cold after you do so, outside, on a porch, unheated garage, etc. Bringing a cold gun inside can attract condensation that can then refreeze, and it doesn't take much ice inside a bolt to cause just enough friction to be an issue. If you bring it inside just be sure it is there long enough for any moisture to evaporate.