This is what it says about Affinage Eraser on Angelina's site anyway...
"We use Affinage Eraser. Affinage Eraser is a unique approach to removing unwanted or incorrect permanent hair colour. Eraser has a thorough but gentle action which preserves the hairs natural condition leaving it perfectly ready to receive a new colouration.
Fast action, removes artificial colour only, kind to natural hair, improves condition and gives it great shine.
We also use L'Oreal Effasor which is not as gentle as Erasor but can effectively lighten your own hair."
So it sounds as though it is fairly gentle compared with L'Oreal Effasor...