[ionburn]

I tend to run a craft knife (the blunt side) along Veroboard to clear the space between tracks then brush with an old toothbrush. If I am really trying to clear things to spotless I use a cotton bud soaked in isopropyl alcohol then brush with the toothbrush.

I do use a paintbrush for dust around components, sometimes using it with isopropyl dependant upon risk to components.