There are many things in the IF#2 that could be 'doing it', but the most likely (methinks) is the Slippery Elm (it's known to be fantastic for dissolving tumors of all kinds).
So, perhaps if you switch to straight slippery elm (or alternate days with the IF#2), it'll disappear even faster! I'd mix the slippery elm with aloe gel if you have it...even though sebborheic kerotosis isn't malignant, aloe gel will dissolve (even heal) the lesser skin cancers sometimes. So the slippery elm/aloe gel is a major winner for skin issues!