Ballistol, Armor All, RIG, Bianchi-Intl....
For holster/gear TLC, I suggest buying some great Ballistol, Armor All or maybe some RIG(which I think was purchased by Birchwood Casey about 2/3 years ago).
Ballistol can treat most leathers, polymer, Kydex, etc.
Be careful about the inside of holsters but that should do fine.
Read the holster/gear owner manual too.
Some cleaning/care products may stain or darken the leather.
The late Walter Birdsong;
www.black-t.com once told me how leather/gear care was important & a factor that many "armed professionals" overlook.
CF