Wool naturally repels dirt and moisture, but if your hooks need a little more than that, just wipe gently with a cool damp cloth. We keep it clean by using wool and wood, which are both natural and sustainable resources. Longer Bolts: Each hook purchase includes a standard 1.5" hanger bolt for brick, drywall, or concrete installation. However, if purchasing a larger order of hooks, or if you are certain you will be installing through drywall and into a wooden stud, consider adding a pair of these longer 3.5 " hanger bolts. https://www.etsy.com/listing/1113415579/ Install: Directions are included. Please follow them, as using the wrong drill bit size or tool can cause the anchor to not work. Do NOT over drill the drywall. If you are having difficulty, please contact us so we can help troubleshoot. ++These wool ends are handmade which means there may be slight differences in their character (shape, sizes, or density), and slight color variations between dye batches. All the same function though... and all the same great look.