This addon provides a simple solution to be able to quickly switch alpha textures for the sculpt brushes.
Once the addon is enabled, you have to be in Sculpt Mode, then go to Properties Editor > Active Tool tab > Texture Panel.
Note that the addon does NOT come with a library of alpha textures, you have to supply your own.
To setup your folders, follow the instructions you’ll find in the addon’s preferences.
Download it from here:
And last thing, if you find this addon useful, I’d be happy if you could upvote my proposal at Right Click Select, so Blender devs implement a similar (and more elegant) solution as part of official Blender’s workflow. Thanks!