1. You might want to plunger itSoap scum is the enemy. Removing all the lather deep inside the brush is important if you want to keep your brush at it’s best. Not only should you rinse it out thoroughly, but you should force water deep into the knot to clear out the last bits of soap deep down inside the brush.
How? By filling a cup with water, and plungering the brush until the water runs clear. Here's a video of me demonstrating the technique.
2. It dries faster upright!Contrary to popular belief, the fastest way to dry it is actually right side up (hairs up, handle down). Not in a stand hanging upside down.
This is because of the way the water leaves the brush. Once the brush has been squeezed and shaken, the primary means of water loss is evaporation. Not gravity. Unless you hang your brush dripping wet (and you really shouldn’t) there isn’t enough water to form droplets for gravity to work. Hanging it upside down stops evaporation from being able to work properly.
You can see this in action if you have two cups (or baby bottles). Turn them upside down to drain out the water. Then leave one upside down and the other right side up. The one that allows water to escape upwards will dry faster.
But fear not! Most brushes will dry out completely within 24 hours either way. Dry it gently on a towel if it’s a concern to you. And if you want it to dry within a few hours, just put a fan on it. The moving air will dry that brush pretty darned quick.
3. It can benefit from a deep cleaning every once in a whileSoap scum is the enemy. And even if you plunger it and rinse it thoroughly after every use, soap scum will still build up eventually. But fear not! A simple 50/50 mix of vinegar & water plus five to fifteen minutes will break up that scum and renew your tired old brush. But if you don’t want it smelling like vinegar, something like MAC brush cleaner will do the job too.
4. They won’t last forever
The simple truth is that while that acrylic handle may well last hundreds of years, the knot will not. It is made from hair and unless it is kept under the most rigorous preservation standards, it just won’t last. And neither will the glue.