I use a leather upholstery cleaner for vehicles. Purchased my sofas in 2009 and they will look like new.
Use leather cleaner and conditioner only.
I wipe mine down with a damp cloth, if needed I use saddle soap as that is what I was raised to use on all leather. Some times I apply some polish for fading or scratches: https://www.hometalk.com/42335424/scratched-leather-repaired-ez