If you're in the US, I highly recommend Cadillac leather wipes. Nordstrom carries them and they are the best one that will wipe off dirt without wiping off the leather color. I've used many leather cleansing creams before and they ended up with some color loss. Cadillac is the only one that will clean (and you can tell afterwards) and condition without damage to your beloved H bags.
Just ordered this for my bags as well as my H shoes.. Thanks so much for the tip!!