Hi Gay. I like to use a leather cleaner product Weiman. I spray it onto the chairs and then use a soft cloth to rub it in.
Does it clean up heavy dirt or just surface stains?
This will help: https://www.topcleaningsecrets.com/house/how-to-clean-a-leather-sofa-at-home.html
I purchase my leather cleaner from automotive store or WalMart's automotive section. Vehicle leather is subjected to much more brutal conditions than household furniture so it goes above & beyond. I've had my leather sofas since 2009 and they still look brand new.