Fire damaged grandfather clock
For the exterior, Murphy's oil soap and water, using rags. If this doesn't clean it up, try ordinary paint thinner - it won't hurt the finish.
For the interior, you have a couple of choices - but before you can use any of them the works of teh clock must be removed from the head. No, you can't just take the head off - the smoke smell is inside it, too.
The quickest cure would be to reseal the interiorof teh case - completely. I'd suggest an aerosol shellac. Once the case is sealed, the smell of smoke will be gone.
Saving Fire Damaged Furniture has a list of things to buy.
Next, place the steel wool in the cup and let sit for a few minutes.
How to clean wood furniture after a fire.
What do professionals use to clean smoke damage
How to Remove Soot from Wood Surfaces.