You need to be careful using the Magic Erasers.. They don't really "erase" anything. The reason that they remove marks and stains is because they remove surface layers of the canvas or leather.
If you use it too much, it will result in a grey, dull finish on the Vachetta. Overuse on the Monogram Canvas will wash out the print and on leather it can remove the dye pigmentation resulting in horrible fading.
Since you have already used it with negative affect, I suggest ordering leather care and rejuvenator from Griot's Garage.
http://www.griotsgarage.com/product/car+care/interior+detailing/leather+care,+8+ounces.do
http://www.griotsgarage.com/product/car+care/interior+detailing/leather+rejuvenator,+8+ounces.do
Apply both with your bare hands and "Moisturize" it in to the leather.
Massage the "Leather Care" in for a good 5-10 minutes until the leather darkens. Clean it off with a clean, soft cloth. You should do this to all of the vachetta so all of it is evenly toned. Let it set for 15 minutes and proceed to the "Rejuvenator".
Again, massage the rejuvenator in with your bare hands, making sure to cover all of the vachetta. You will immediately see a change in the texture of the leather. Let it sit for a few minutes and allow it to absorb into the pores. Wipe the leather clean with another clean, soft cloth (Not the Leather Care).
You can use both of these products on the Monogram Canvas, Damier, etc. It will NOT harm any of your items - As some of the other products on the market do.
This is THE finest product I have ever used and is the ONLY one that I will use on my bags and in my car.
You will be amazed with the results.