In this Instagram posted by customaudioeletronics, one of John Mayer's pedalboards (the one on the right in the photo) has an Electro-Harmonix POG2 pedal on it.

Brand new #johnmayer rig heading to #Albany for production rehearsals! #customaudioeletronics #bobbradshaw #thinkloudstudios

"Sometimes, I use a POG pedal. I think I was the first person to record with one on the White Stripes song “Blue Orchid.” Electro-Harmonix sent me one as a present when we were recording Get Behind Me Satan. “Blue Orchid” came out two weeks after the session, so it had to be the first song to feature the POG. I use it to add the first and second octaves below, and one octave above the root note. It’s four of the same note simultaneously. It’s just so heavy. The riff is actually pretty simple, but it’s all about the one. It’s a funk-based idea."

The pedal was mentioned in the 2019 Premier Guitar interview.

In this pic from his reddit AMA, Kevin shows a POG2.

In an interview with NPR, DeMarco explains the sounds featured in his song Without Me. He says, "[I tried out] this really weird, strange, warpy octave pedal on this song. It just kind of makes your guitar sound like a weird church organ or something strange. It's a cool thing. It's a weird, weird sound."

This particular pedal was spotted onstage during the 2016 North American tour as part of Andy White's setup, and used for the song Without Me.

In Fender’s YouTube video Kevin Shields of My Bloody Valentine - Part 1: Obsession, the Electro-Harmonix POG2 Polyphonic Octave Generator is visible at 1:16 and can be identified by its shape, color, and the white knob at the top right.

This photo from a Royal Blood live performance shows Mike Kerr using an Electro-Harmonix POG2 Polyphonic Octave Generator guitar effects pedal.

Guitar World, 2020

“Well, I know you use an Electro-Harmonix POG2 and a Z.Vex Mastotron Fuzz,” I venture, to which Kerr counters, “There you go then. So you know all you need to know.” I bring up the matter of Kerr’s “mystery pedal,” the identity of which he swears he’ll never disclose.

Used during the recording of Drones

According to this article by Premier Guitar, Geddy Lee used a POG 2 on the song "The Anarchist."

An Electro-Harmoinx POG2 can be seen on Josh Klinghoffer pedalboard, in this photo.

J Mascis talks about his POG2 pedal in this video interview. At 16:16, he says, “I just got that for this tour to try to replicate sort of some of the sounds I had on the records. I played organ on one song and guitar synth, kind of melatron flute, on another song and I can get kind of close to those two sounds with that pedal.” J demonstrates the POG at 23:26.

"The thing I’ve been really excited about lately that I saw the guys in Soundgarden using at their rehearsal is the POG2—the Poly Octave Generator. I’ve been doing a little bit of scoring and I worked on an episode of Shameless and did this movie Fat Kid Rules the World and ended up using the POG on a few things because it makes the guitar not sound like a guitar. It makes it sound like a weird calliope or an organ—kind of makes some cool sounds."

An Electro-Harmonix POG2 can be seen on Tim Commerford's pedalboard at 0:28 in this video.