I would try Seed & Boundary or Solid Surfaces RMB.
Click on a surface (Left click), to select the entire feature.
Left click again on the same surface. That should select just the surface.
Press and hold <Shift> and left click an adjacent surface. Release all the buttons and all the surfaces should be highlighted, with the exception of the last one you clicked on.
Press and hold <Ctrl> and left click that final surface. Release the buttons and all the surfaces are selected.
It's far more complicated to describe it than to do it, especially once you have done it a couple of times!
An alternative, much simpler method is:
Click on a surface (Left click), to select the entire feature.
Left click again on the same surface. That should select just the surface.
Right click and select Solid Surfaces.
The only problem with this one is that it doesn't always seem to offer the Solid Surfaces option. There is probably a well-defined set of rules for when it is there and when it is not, but I don't know it.
Solid Surfaces: Very quick and easy
Seed and Boundary: Probably works more often
- I should have said - between the first left click and the second left click (to select the surface), you have to move the mouse a fraction of a millimetre, otherwise it doesn't register the second click.
This is all based on Wildfire 2, so later versions may vary. I doubt it, though.
Give them a try.
Cheers,
John