Vertical lines on gutters “tiger stripes” will not be removed with our Softwash process. These vertical lines are a form of oxidation. Our softwash process treats organic growth only. We do not offer oxidation removal as a service. Our softwash process DOES NOT remove oxidation from siding. If you rub your finger across the siding and it leaves a powdery residue on your finger, this means the siding is oxidized. We do not offer oxidation removal as a service.