Can a Doctor operate on his own appendix?  Yes, I guess so.  But I doubt if many do. 

The help of a living Master is essential if one wants to realize the Truth, according to almost all of the Masters, saints, seers, etc.  Of course, the student needs to trust the Master and make effort to go within. 

After all, that most subtle foundation of life is not easy to experience when the ego-mind is active.  Only in the stillness can one really understand this.  Not when the internal dialogue is going yap-yap-yap!