The brushes I use for applying oil paints and stains are among the most expensive I own. It is not hard to spend upwards of $20 for a good brush. I clean them with mineral spirits. It does not take long to dip them in the mineral spirits and remove the gross paint, then use clean solvent to finish cleaning. I use a rag to clean up into the head of the brush and absorb solvent and paint from the brush then store the brush in the envelope it was sent in to let it dry and hold its shape.
Solvent soaked rags are a fire hazard, so don't let them sit in the sun or a pile in the garage. If you use cheap brushes or foam pads, toss em; if you use quality brushes, take the time to clean them and they can last a long time. I bet Henry from MI has brushes that are older than you are! What do you think Henry?