

What does grungy mean to you? Is it patina on full grain leather? Is it the thinnest leather stitched by a machine that as started to fray and tear? Is it paint starting to rub off?
Better quality wallets are saddle stitched by hand using full grain veg-tan leather or other leathers from reputable tanneries. The edges are usually burnished and not painted. They will patina nicely but will have to be cleaned and oiled at least once a year.

It doesn’t need go be a very thorough cleaning unless its very dirty.
Simply water and leather soap. Then some conditioner after.