>>1334801The pull through sharpeners only ruin the apex and surface of the bevel, a regular resharpening will fix any damage.
I'm not sure how well the mouse pad method would work with a thin small edge like an Opinel. If you don't have any bench stones, well fix that the double sided Norton Indian stones are only like $20, sand paper will work, I would recommend putting it on a hard flat surface (stone or glass table top ideally), and wetting it with some water. A normal "V" grind will do, but if you want to try convex, go for it. If you mess up, you can always fix it latter, or get a new one.