thanks for your response.
I heard on some forums that's the water can make the leather becoming dry and start to disintegrate over time, maybe some sorte of cream or oil for skin can make the trick ?
Never cleaned my G25 in 6 years, apart from just dusting it. Still looks & smells as good as new.
EDIT: I always wash my hands before I use it by the way, that probably helps.
I always wash my hands as well, but having sweaty hands doesn't help lol. I tried using gloves in my early days, but I find it reduces touch sensitivity too much.