I know what it is but whats the reason for them?
The video makers statement at the 8 minute area says it will help prevent live bait from tangling the line. I assume he means the drop line getting wrapped around the main line between the bobber and the reel. But he also says the bead is slightly magnetic so will stick to lead. My understanding of metallurgy might not be up to date but that just ain’t right. It might stick but it ain’t a magnetic attraction.
I have never tried this straw method so can not verify what it will actually do.
good luck with your search.