EQ III is still a good go-to EQ for corrective EQ. I think some people write it off unfairly and I see a clear trend in the post community to still use it with the music community favouring third-party equalisers.
Boost, Drag, Invert
A very popular technique for quickly identifying problem frequencies is to boost across the offending area, often by dragging the control point and then cutting at that frequency. I'm a little old school in that I tend to use the knobs instead of the control points but if you do drag control points it's easy to drag downwards and to unintentionally drift sideways and to end up on a different frequency from the one you originally identified.
Seek And Destroy
By shift-clicking on the control point and inverting the gain it is possible to quickly "cruise" for the offending frequency in boost and then invert it to a cut - destroy!
All this semi-military language makes it sound rather dramatic but it's a genuinely useful feature of EQIII, it works in the 1 band and the 7 band versions (and the 4 band version if you still have that) but annoyingly doesn't work in Avid Channel Strip, which I still see as a good channel strip let down by a limited EQ.
Watch the free video to see this in action.