I have been to every store and talked to all the pros. I have some 20yr old custom oak cabinets, i want to change to a dark mahogany color. i have sanded lightly and have tried sanding to bare wood. I have let stain sit over night and have tried letting it sit for just 20 minutes. after 4 coats I have maybe gone 1 shade darker. I have one test spot with 8 coats on it without much of a change. a sherwin williams rep told me to try a wood softener....can anyone offer any advice please, I am stuck..