If you mean soft edges and less than opaque painting, then yes, that is what you will get with the airbrush, similar to a soft-edged round brush. Use the airbrush at varying opacities and at different flow rates which will give you much better control.
What I am seeing in your example (it would be nice to see an enlargedment but ...) appears to be added noise. I would suggest trying this. Go to filter>noise>add noise. In the window, choose Guassian, monochromatic, and experiment with the amount.
A useful tool when adding a filter to any layer, especially if you think you might want to change it, is to make that layer a smart object or smart filter, and this keeps the filter application editable. Just right click on the layer and choose convert to smart object.
This image may possibly be using the layer mode, dissolve, a mode which rarely has much use, IMHO, but thisd might be one of those times that it is useful (but noise seems a better option).
Let us know if this is taking you in the right direction.