I’ve read the wiki entry on this effect and kind of understand it, but it clearly states I can amplify the clip by dragging the slider to the right. However, as soon as I move even the tiniest bit to the right, all the buttons become greyed out.
I can lessen the volume with the slider, and I can increase it if I just go with the defualt setting and press OK, but any movement to the right with the slider greys out the buttons.
That is technically true, but if you try exporting a file that goes a long way over 0 dB, and then import it back into Audacity, you will see that it is still clipped. (I presume that this is a limitation of the encoder, or decoder, or both).