I've never put polish on an LV button, but I tried putting clear nail polish on a super cheap ring I was using as a stand-in while my engagement ring was being re-sized to kept from turning my finger green. The polish didn't last more than a few days before it started to noticeably chip, and I ended up peeling it all off. To be fair, it may have had to do with the chemistry of the polish against my skin or the quality/type of polish I used (Seche Vite top coat), but my experience of clear nail polish to coat things has been less than stellar.