Unfortunately this script has no preview, so using it is not very intuitive.
Therefor i will show you in todays tutorial how different values applied to the selection look like.
For the example i set up a rectangular selection: 400x300px and stroke it by 6px on a new transparent layer.
After alpha selecting the stroke, you disable the layer, distort the selection and fill it with the desired colour on a new transparent layer.
The 'Distort' script is under 'Selection' and looks like this.
The examples have values for Spread/Granularity/Smooth
If you like even more grunge, apply a small value of 'Spread' to your stroke (say 1-2px).