Some teachers say yes, and others say no. — I believe there's wisdom in both answers.
Speaking personally, I found it useful to strive and pursue — but not to strive and pursue awakening / nonduality. Instead, I was striving and pursuing a more honest life, to deepen my heart and open mind to the truth—regardless of where that led me. When we make that our goal, I believe we sidestep a lot of traps of grandiosity and paradox that come with pursuing "enlightenment"—something that is impossible to "attain" in the regular sense.
Is this something a guide or teacher can help with? Or is this something we need to keep going with on our own? — The answer, I believe, is yes to both. No one can awaken for us. Just like no one can die for us. Or, in this case, live for us. It's something we have to do ourselves. But the times in my own journey that I've made the greatest progress was when I was both working with someone else and also earnestly pursuing the truth on my own.
One of my clients spent many years reading and exploring on his own until he hit a plateau. After several months working together he said to me, "some of this work can only happen in relationship." And I believe that's true.
A guide or teacher can't do it for you. And I don't put much stock in anyone's guarantee that you will awaken in the course of working with them. But if you show up to spiritual work sincerely willing to deepen your heart and open your mind to the truth, whatever that may be, you will find yourself moving closer to the heart of life.