"I got a Whammy Pedal and I thought, Okay, you don’t have to do solos, but it would be nice if once in a while the guitar broke out and had a moment for itself and then went back to the band. The Whammy enabled me to get an octave higher than everybody else, so I could break through for a few seconds and do a lick and then come back to the song. And now I just want solos to be an octave higher and piercing... Also, I like to manipulate my DigiTech Whammy pedal starting with the low octave. I love low octaves. I’ve always loved playing octaves on the piano, even as a little kid. So when they came out with that pedal, and I heard Tom Morello use it in Rage Against the Machine, I knew I’d finally found an interesting pedal."

Premier Guitar:

There’s a thing somebody sent me, because I use a Whammy pedal. I’ve always used it since the White Stripes, but this is a new contraption [called a Step Audio Riff-Step] that you can hook up to the Whammy pedal to bounce between four different settings whenever you tap it. That’s going from an octave up to a fourth down to an octave below to a fourth up or something. It just kind of worked out for that song in a cool way. Now I have to do it every time [laughs].

A 5th-generation Whammy was used for Live at Pompeii.

James Hetfield uses the DigiTech Whammy Pitch-Shifting Pedal, as noted on Groundguitar's "James Hetfield's Guitars and Gear" page.

DigiTech Whammy was in Billie Joe’s pedalboard during the concert at Whiskey A Go Go (09/10/2019). Apparently, it was also used in studio on “Take The Money And Crawl” and “I Was A Teenage Teenager” from Father Of All... album.

The DigiTech Whammy Pitch-Shifting Pedal is part of Matthew Bellamy's pedalboard setup. He especially used it during Muse's Resistance Tour in 2009, as can be seen in this photo from that period.

I’ve never used or owned a distortion pedal. It was just the guitar and cable straight to the amp” – EVH

That being said, Eddie did use a couple of other effects in his chain. He used a MXR Phase 90 and MXR 6-Band EQ at the beginning of the chain, and some other effects like Echoplex EP-3 Delay, MXR Flanger, and Univox EC-80 Tape Echo closer to the end of the chain.

These days Eddie uses somewhat different rig. He has a couple of his own signature pedals from MXR/Dunlop in the chain – like the EVH117 Flanger, Phase 90, and the EVH95 Signature Wah – and some other pedals like the Boss OC-3 Super Octave, Digitech Whammy, and MXR M234 Analog Chorus.

According to this 1994 interview with Guitar World Magazine, Dimebag Darrell uses a Digitech Whammy pedal to affect the feedback on the song "Good Friends And A Bottle Of Pills," as well as a few other tracks. " I discovered the pure feedback wasn't quite enough, so I added a Digitech Whammy Pedal to the equation, which helped produce a sound that was completely fucked up!" he said.

In this photo, we can see Gallagher's pedalboard, which has the DigiTech Whammy. This pedal has been used for the end of "The Shock Of The Lightning", and it can be heard on Wembley 2008 performance.

The DigiTech Whammy Pitch-Shifting Guitar Effects Pedal is part of Steve Vai's pedalboard.

In this MusicRadar article, the Edge's tech, Dallas Schoo, discusses Edge's rig for the 360 tour. The WH-1 is listed on among the pedals on the Edge's main pedalboard.

Jerry Cantrell uses the DigiTech Whammy Pitch-Shifting Pedal, as noted in the Groundguitar article "Jerry Cantrell's Guitar Gear." This pedal is part of his extensive collection, which includes other notable effects like the Dunlop Heil Talkbox—famously used on "Man in the Box"—and the Electro Harmonix Big Muff Pi, featured on his solo album "Boggy Depot."

In this image from a studio session, Smith is adjusting the parameters on a pedal. His Whammy pedal is sitting on the far left side of the picture.