Kakuzu's main body uses Earth, so I don't think that Kakashi wants to do that.you got ride of kamui by strange way
so should i say kakazu can't use his hearts or jutsus because he has never killed character with it?!!!!!!!!!!!!!!
kakashi has kamui and he has the right to use it in any time
even without kamui ,it won't be low diff to kakazu and hidan ,kakashi has sharingan's ginjutsu which neither hidan nor kakazu can counter
kakashi can counter kakazu's hearts's attacks(fire,wind,light) by going underground