Dirty little secret - I've been cleaning shells with a damp cloth followed by buffing with a torn up piece of towel for 20+ years (learned it from a shoeshine guy that polished my father's Aldens - he started wearing Alden shells in the 50s/60s). Do I have a horsehide brush? Sure. Do I use it? Can't remember when.
Rule of thumb - if you are scratching your shells using a horsehide brush, you're brushing too hard.
i have been brushing with a horse hair shoe brush for 50+ years and i had never had the issue of brushing too hard