How to apply a textured stroke?

[jeljohnssp]

I'm trying to figure out how to achieve the subtle texture on the shapes below. That artist said in an Instagram video that he creates the flat shapes in Illustrator, then brings the file into Photoshop to apply the inner texture with a brush, but he didn't explain how he achieved the stroke which looks like it was hand drawn. I cannot figure out how this is done. 

[Trevor.Dennis]

This would do it to some extent, but I think I am seeing Ocean Ripples or Glass in those transitions

OK, this has a solid blue layer with a black to white gradient, and the layer mask has the Distort > Glass filter applied to it.  Ocean Ripple is similar, but scaled up a bit.  Incase there some people not aware of this, most of Photoshop's effects can be used on Layer Masks, or with Quick Mask.

Are you OK addapting this to the sort of graphic in your example?

[jeljohnssp]

The artist said in an Instagram video that the inside texture was done with a brush. I'm trying to figure out how to get the texture on the stroke, which makes it look hand drawn. That's the part I can't figure out after an exhaustive search.

[davescm]

You can add a texture pattern to a brush in the brush settings panel. In addition, setting the brush blending mode to dissolve creates rough edges when used with a soft brush

Dave