In this tutorial you can learn how to create Photoshop Dispersion effect in different way – Text Dispersion. It is a bit tricky but in the last steps it is almost the same as classic Dispersion effect.
All you need to do is to create your own brush from text. This you can do in new document where you need to type your text with black color and white or transparent background. Then go to Edit -> Define Brush preset.
Now you have brush from your text so you can go to your project and start with your Dispersion effect. Watch whole process in my tutorial: