DIY Sisal Bristle Oil Brush

I recently have been doing a lot of drilling through metal which requires cutting oil to keep the bit sharp . I’m using used air compressor oil (stored in a plastic water bottle) and I needed a brush to apply it. The silverfish ate the bristles of all the old brushes I had stored in the shed, so I decided to make my own. I made a brush out of sisal twine, aluminum tubing, and an old screwdriver. It's hacked together but it works quite well. The section of sisal twine is held in place inside the tube by a screw. When the bristles wear out, it is easy to replace with a new piece of twine.