Whenever you use something in a method it's
: not intended you risk failure.

I find this an interesting statement (no offense). The nylon we use is not intended for boats, and the Zar or any other brand of poly we use is not intended for boats either.
I've used dental floss a couple times. Its cheap, readily available and it works. Even if poly does not bind to wax, its coats is so much that its a non-issue. It will break at some point in time in your sewing process, which isn't a tragedy. Once you coat your skin, the seam is welded together and it will not separate, so strength is not important.
Don't over think it,
Scott