The baking will kill whatever's there (be prepared for a stink) but leaf mealies and root mealies are two different insects (maybe the genus is different, too). No, leaf mealies don't live in the soil, as soil mealies don't live above the soil.

Baking the soil should work:)

Thanks both, I would like to pass on the baking but if I have no choice I will give it a shot. How long can leaf mealies live without plants? I remember when they were around Id see one on the corner of my pot, so they were not restricted to just leaves. Ive not seen a topic like this on the net either, so either Im the first one or Im doing something wrong.