Bush-On Flat Coat Gone Horribly Wrong...

[Gluteus Maximus]

Dull-coat has long been one of the things to use - and if you're concerned about clouding and white specks the old trick of putting the can in a bowl of hot water for awhile before spraying really helps eliminate a lot of problems with it. It helps build the pressure in the can so the paint atomizes more thoroughly and also seems to get the paint to mix more completely when shaking the can. Whenever spraying any Testors paint I always do this - but especially with the clear coats, both gloss and flat.

Well, I never knew that! Just goes to show you never stop learning 

[Pil]

Since we're on the subject, how does dullcote stand handling? I use a cheap matte varnish (Brico) which works quite well, but it also wears quite easily, becoming shiny in spots that are handled a lot. How does dullcote compare or is it a general issue with matte varnish?

[Malebolgia]

As a friend of mine once said: Dullcote is as protective as a leaky condom.

Always use 1-2 layers of gloss varnish (for example car varnish) and then dullcote. I use this on my gaming miniatures and they rarely chip.

[redzed]

is it a general issue with matte varnish?

matt varnish doesn't really protect, the actual strength of the varnish has been diluted by adding matting agent to it.
Always use a gloss varnish first.