Paint Brush Cleaner

It might be hard to capture exactly what it does in pictures, but essentially it has a slot you slide your brush into that pinches and wrings the brush. Fill with some water or paint thinner, and it should help you get most of the paint off without a mess. Should also use paint thinner more efficiently.

Make sure to print in the proper materials as to not melt the plastic, and print thick enough so that it doesn't leak. I printed at 1.2mm walls @ 0.2mm layer height @ 20% infill and it's 100% waterproof.

The brush slot starts out at 1mm wide and shrinks down to 0.4mm. So keep in mind that if you want to use it for large thicker brushes, scale it accordingly. This size is more suited to smaller detailing brushes, but can work with larger brushes too. Can easily hold multiple brushes, which can be cleaned one by one without interfering with each other. It's really a more convenient design than it looks at first glance.