Chrome Oxide was an alternate technique to go for 'tape grunge', originally sold as a separate plugin. It worked like this: it threw in a random noise, but instead of just overlaying the noise onto the sound, it used the noise to interpolate between the current and previous sample.
What that did was noise up the treble of the sound, and the steeper parts of waveforms, leaving the silence and flat areas of waveforms alone. It very quickly affected highs, and turned everything to a roaring grungy mess. Small traces of this effect are still used in Iron Oxide, though it's not being sold standalone anymore.