Although we have tried this ourselves, we have heard users have successfully applied Veil in this manner.
I believe Veil is sufficiently "thin" as to not require further thinning for use with an air-brush.
We have made large strides over the years to improve the application performance and appearance without needing such a device but we will continue to evolve Veil in its application so that, perhaps one day the "need" to do so to obtain the best appearance will be largely eliminated.
In the meantime, short of using a air gun, if one were to apply Veil with one of its foam brushes starting at the top of each housing and working oneself towards the lower section using single and smooth brush strokes should go a long way to maximizing its appearance.
Applying Veil (in either case) during the early morning or later hours when it is cooler should also allow Veil the best chance of setting up properly.
My recommendation would be not to overstroke your application and let gravity work for you.
Please let me know how you fair with either approach.