I don't see why not, I know many people who do it. The only problem you might encounter is whether or not your hair likes heavy butters, which not everyone does.
To me it's both a moisturiser and a sealer, you can mix it up with different things and change the consistency to make it lighter for a moisturiser, mix it with fewer things and keep a butter consistency or use it raw. There are many moisturisers that contain shea butter.