When Lars and Ram from Colourlock came by and showed me their techniques for cleaning leather and Alcantara, I was intrigued ny this simple little brush that just works well.
Since their visit, I've been using this brush for everything on the interior from the leather to Alcantara in combination with Sonax Alcantara Cleaner and the Swissvax Leather Cleaner. According to their website, it's made from recycled PET and won't rot if you don't dry the brush out all the way.
You'll receive either a ColourLock or Swissvax brush (They're the same exact brush, Colourlock makes them for Swissvax). Sometimes I cannot get Swissvax brushes fast enough so you might receive a ColourLock Brush. Sometimes I cannot get Colourlock brushes fast enough and you might receive a Swissvax brush.