That won’t wash as an apologetics argument with n-Cs since they consider it all ultimate authority. If you use it they will immediately accuse you of not believing the Bible, (something they already pretty much “know” about us Catholics). Naturally that is not at all true…
Ecclesiastes is one of my favorite reads. It’s a mystical book that covers so much more than just philosophical musings, though they are also there.
It is full of insights into Jewish thinking.
Here’s an personal example.
Many years ago I had a wealthy Jewish friend whom I trained privately in Karate and we often chatted all kinds of things. One day we somehow got on the subject of the messiah and his coming and I mentioned that Muslims in Jerusalem had buried their dead outside the Eastern gate intentionally because of OT prophecy is that the messiah will enter that way and Jews cannot pass through a graveyard.
So I asked him if Jews believe in a resurrection of the dead (thinking about the resurrection at Christ’s return would make that a moot point) and his answer was no.
See how that passage shapes and sums up their thinking?