We don't need to look anywhere outside of this very moment. Looking for spiritual experiences will always lead to frustration - if they DON'T come then there is frustration. If they DO come they inevitably pass, then there is frustration.
Any experience will do. And what better experience than this one, right NOW?
So Nonduality means not-two. That doesn't mean that there IS two and then, through analysis and more mental acrobatics, the two is magically spliced together and then there is Oneness.
Not-Two is NOW. THIS. THIS is Nondual. Whatever THIS "appears" to be, whatever THIS is interpreted AS, doesn't change the inherent Oneness.
So THIS RIGHT NOW is called "reading a blog." Yet the assumption or interpretation is "I am reading a blog." Subject/object equation. Duality. The interpretation itself IS duality.
What do you know prior to ANY interpretation? What is obvious without any necessary concepts? You ARE. You KNOW you are. YOU are self-evident. No proof is necessary. No concepts are necessary to know.
But HOW do you know? Aren't you certain of your existence because of the activity of experiencing? Isn't what-you-are actually this present experiencing, that is going on RIGHT NOW? And IN this experiencing, experience comes and goes.
We might call this experiencing "Consciousness"... and we might see that Consciousness can never be separated from experience. In fact, Consciousness IS experience. No seer or seen.