For the Photoshop difference cloud filter, apply to an existing layer or image but if you want to use to create a seamless tile then create a document with the size 128 * 30 by 128 * 30 or 128 * 20 etc, if you want a very big document, multiply by 100 etc and then use that as the pattern.
Set the color via the foreground color and background color so go for a combo of yellow / red or black / white etc and you can always change it at any time and re-apply.
Go to the filter menu and render and apply the effect, you can then just use the top repeat command to re-apply again and again after that.
There is one option that you may find of use, hold down the alt / option key as you apply the effect to create a more high contrast effect and again keep re-applying it over and over and you will still have your tile which can be saved to the presets via the edit menu and define command (you can also just define it as a brush as well). You can also combine with other effects such as oil paint and wave.
You can also use the edit menu and fade and use blending modes with the effect such as lighten or darken etc. You can also create a new layer (fill it with something such as white) and then apply the effect again and again and then go to the layers panel and change the blending mode etc.
You can also combine the design with adjustment layers via the layer menu and new adjustment layer to re-color it or perhaps turn it into a black and white image and more. Use as textures for displacements etc