how to clean the white leather

I would personally not risk leather cleaner on the Heritage line. The reason is it's like the Madelines...the dye is not cured that well, and it has a tendency to lift fairly easily. I guess white may not be as bad as some dyes, but I would really try conditioner or a damp cloth first..sometimes you can use a tiny bit of gentle soap like Dove. Don't get it very wet, and don't rub hard. You can spot the leather with too much water or soap. Leather cleaners are harsh..at the very least I would dilute the heck out of the cleaner before proceeding. Sometimes I just use conditioner and tape, but it just depends on whether it's color transfer or just light dirt, etc.
 
I also use alcohol free baby wipes. I get most of the dirt off of my white Ali using this. I also condition her with Apple conditioner OFTEN. I think this removes light dirt and makes it easier to remove soil in the future.
 
Yeah. Definitely DON'T use baby wipes w/ alcohol!! I would try a little gentle soap and water with a touch of baking soda or borax and rub VERY gently with a soft cloth. Or maybe try the coach leather cleaner or apple leather cleaner? Whichever method you chose remember to moisturize it well after it dries. That's very important.

In a worst case scenario if the white starts to lift (something you're hopefully not in and hopefully won't be in) you could use a little white shoe polish to restore it.