A luthier friend of mine recommended clear nail varnish on a “battle scar” on one of my guitars - I dropped a strobe tuner on it - ostensibly to keep the muck out of it until such time as I could get it properly repaired; it’s finished in nitro.

To the o/p - Unless you’re set on keeping the instrument in showroom condition, a bit of honest wear can add mojo to an instrument. There are also those who scrape all the finish off a guitar neck to produce a so called “speed neck”. The aforementioned guitar of mine had one such neck when I bought it - I had it re-finished.