Justin does uses this pedal! Here is a photo of JUSTIN'S bass pedal setup from Tool concert on May 8, 2019 at the KFC Yum Center in Louisville, KY.

Buckethead can be spotted using a Whammy II, (not 5 as someone else has noted) during this performance and most, if not all past present and future performances. You can see the black pedal to the left of his FM4.

You can hear Troy scrolling through the harmony presets at the beginning and you can see the toggle mode light of the Whammy II when the camera pans down

In this screenshot of the Tibetan Freedom Concert in 1996, we can see the pedalboard of Pat, it is composed of a ProCo Rat 2 (see one of my previous submission), a Arion Stage Tuner (we can clearly see that it’s the Arion Stage Tuner), a Boss BF-2 (sure it’s the Boss BF-2 because of the shape and color of the pedal but also of the live at Concert Hall 1996, where during the noise part of Exhausted we can ear a Flange effect), and a Digitech Whammy II (sure it’s a Whammy II because of the shape, footswitch, and color of the pedal).

Listed on the official Buckley site, as stated by former Buckley tour manager.

Seen in this rig rundown video at 5:46.

James began using a Digitech Whammy II in his live setup starting with the touring for MCIS. In an April 1996 interview with "Guitar School" magazine, Billy states "...there is a bunch of Whammy on the record. James uses a Whammy for his solo in Zero."

James also said the following in a December 1995 interview with The Guitar Magazine (TGM) magazine "We tried to be a bit more obtuse, varied, and interesting. Like on XYU I was using a whammy pedal and I kept getting these intermittent breakups-like dang-dan-dan-dan-dang-dan-dan-dan-dang-fllllplplplplplsh! You just step on the pedal and it destroys the sound! It's like a tape machine going haywire or something."

Scott's 2003 rig diagram which includes a DigiTech Whammy II.

At 0:35 in the YouTube video titled "Bootsy Collins Tours His Incredible Home Studio 'The Boot Cave'” by Reverb, a DigiTech Whammy II pedal is visible on a pedalboard in Bootsy Collins’s studio setup, confirming its use by the artist.

"This is the input right here. Then it splits off. This is the bypass switch for the Whammy. Then out of the Whammy and into the tuner," says Mike Campbell's guitar tech when the Digitech Whammy II Guitar Effects Pedal is shown in the rig rundown.

Trey most frequently uses the pitch bender, which allows the user to bend pitches using the expression pedal to various degrees up or down. Trey almost always uses this feature in its middle position, which is 2 half steps down. So by depressing the expression pedal, the guitar tone sweeps down two half steps, eg, from an Bb to an Ab. Then as your sweep the pedal back up, the tone returns to the original note. In early 3.0, Trey was experimenting with this sound, dubbed the “Whale,”

According to an article on Guitarthai, in addition to his own signature ESP Eclipse lineup, Sugizo also used an ESP Horizon, Fender Jaguars, Fender Stratocasters, Fender Telecasters, Gibson ES175, a Gibson Les Paul Custom, a Richenbacker 330, and electric violins made by Kranz.

He also used Diezel VH4 head, a Mesa Boogie Dual Rectifier head, a Mesa Boogie 4x12 cabinet, a TC Electronic TC 2290 Rackmount Dynamic Digital Delay, Decimator ProRack G power conditioner, a script Phase 90, a Boss CE-2 Chorus pedal, a Boss OD-1 pedal, a Providence Final Booster, a Digitech Whammy II, an Eventide Pitchfactor, an Eventide TimeFactor, an Eventide ModFactor, a TC Electronic G System, a Boss PS-5 Super Shifter, a Blackstar HT-DIST Distortion pedal, and a Providence Stampede Overdrive.