Just a heads-up: the documentation still refers to version 2.2, but the current version of the addon is 2.7
Grunge
Procedural grunge. It can be applied to both surface and volume
Settings
Scale – Size of the noise.
Contrast – Contrast.
Roughness – Roughness is like noise in a node.
Detail – Details like in the noise node.
Min/Max – The minimum maximum value can be called the contrast for the internal 2 noise.