Well. I have never tried (or heard) the purple humper before, but I have tried something that may be of benefit to those looking to "hump" their rig.
Here is my challenge to you who have heard the humper, have a humper or own a EGDM (or any combination thereof).
What I am interested in is: can the EGDM be used as a "boost" pedal to alter the tonal spectrum of your rig to get a "humped" tone?
Earlier, I tried using my EGDM as a boost. With the Dist @ 7:00, or so, I varied combinations of Volume, Voice and Trimmer to achieve various tone shapes. I found that with certain settings, I could turn my Deluxe Reverb and Strat into a mid-boosted rig. I have no clue if this character is similar to that of the PH, but I was very pleased with the results I got.
At the very least, I recommend you try to use the EGDM as a boost pedal to see what you can come up with. Explore!
Cheers.