I don't actually understand what you're pulling me up on. When I said 'paint on the image' or paint 'in the image area', I simply meant to paint in the document window that contains the image. If I had advised the OP to first select the image layer in the layers palette, and then start painting on the image, then of course there would be a problem (i.e. a black image). But I didn't do that.... I just said: select the adjustment layer, select a black brush, then paint out the adjustment.
This is it Elliot, my last reply. I believe this quote sums it up very well. "
I simply meant to paint in the document window that contains the image " My point is this - the "document widow that contains the image is totally separated from the adjustment layer. As a matter of fact it is always below that adjustment layer. Therefore, painting in the "document window / layer" is exactly the wrong thing to do. For the desired outcome one has to paint (either black or white) in the Adjustment Layer Mask. It is that simple. I rest my case.
Have a great day