Since people are suggesting (defensive) Talonflame as a Defogger who can force Gholdengo out, may I suggest a Defogger with the same typing that's a lot less passive -
Oricorio(-Baile)!

Oricorio @ Heavy-Duty Boots
Ability: Dancer
Tera Type: Electric
EVs: 4 Def / 252 SpA / 252 Spe
Timid Nature
IVs: 0 Atk
- Defog
- Quiver Dance
- Hurricane
- Revelation Dance
With its somehow decent base speed stat of 93, Oricorio naturally outspeeds Gholdengo and Great Tusk and can nail them with these:
252 SpA Oricorio Revelation Dance vs. 0 HP / 4 SpD Gholdengo: 260-308 (82.5 - 97.7%) -- 25% chance to OHKO after Stealth Rock
252 SpA Oricorio Hurricane vs. 252 HP / 4 SpD Great Tusk: 488-576 (112.4 - 132.7%) -- guaranteed OHKO
And that's
before Quiver Dancing!
Oricorio-Baile, like Talonflame, takes advantage of most Great Tusk sets lacking Rock-type coverage and most Great Tusk and Iron Treads sets lacking Electric-type coverage not named Volt Switch by setting up in their faces even if it somehow doesn't force either of them out:
252+ Atk Choice Band Great Tusk Ice Spinner vs. 0 HP / 4 Def Oricorio: 192-227 (65.9 - 78%) -- guaranteed 2HKO
252+ Atk Choice Band Great Tusk Knock Off (97.5 BP) vs. 0 HP / 4 Def Oricorio: 233-275 (80 - 94.5%) -- guaranteed 2HKO
252+ Atk Choice Band Great Tusk Close Combat vs. 0 HP / 4 Def Oricorio: 216-255 (74.2 - 87.6%) -- guaranteed 2HKO
252+ Atk Choice Band Great Tusk Thunder Fang vs. 0 HP / 4 Def Oricorio: 314-370 (107.9 - 127.1%) -- guaranteed OHKO (this actually needs Choice Band, ouch)
0- SpA Iron Treads Volt Switch vs. 0 HP / 0 SpD Oricorio: 94-112 (32.3 - 38.4%) -- 96.9% chance to 3HKO
252 SpA Oricorio Revelation Dance vs. 0 HP / 4 SpD Iron Treads: 324-384 (100.9 - 119.6%) -- guaranteed OHKO (ouch, this is unboosted)
+1 252 SpA Oricorio Revelation Dance vs. 252 HP / 4 SpD Iron Treads: 482-570 (125.5 - 148.4%) -- guaranteed OHKO
Forcing Teras out of sets like these is funny.
When checking Gholdengo, especially Scarf Gholdengo, the only attacks Oricorio-Baile fears are Thunderbolt and Power Gem (and Water Tera Blast, I guess) and bulky Specs Gholdengo Shadow Ball because it's living the rest:
252 SpA Tera Ghost Gholdengo Shadow Ball vs. 0 HP / 4 SpD Oricorio: 238-280 (81.7 - 96.2%) -- guaranteed 2HKO
252+ SpA Tera Ghost Gholdengo Shadow Ball vs. 0 HP / 4 SpD Oricorio: 260-308 (89.3 - 105.8%) -- 37.5% chance to OHKO
252 SpA Tera Steel Gholdengo Make It Rain vs. 0 HP / 4 SpD Oricorio: 177-209 (60.8 - 71.8%) -- guaranteed 2HKO
252+ SpA Tera Steel Gholdengo Make It Rain vs. 0 HP / 4 SpD Oricorio: 195-230 (67 - 79%) -- guaranteed 2HKO
252 SpA Choice Specs Gholdengo Shadow Ball vs. 0 HP / 4 SpD Oricorio: 265-313 (91 - 107.5%) -- 50% chance to OHKO
252+ SpA Choice Specs Gholdengo Make It Rain vs. 0 HP / 4 SpD Oricorio: 219-258 (75.2 - 88.6%) -- guaranteed 2HKO
252 SpA Gholdengo Thunderbolt vs. 0 HP / 4 SpD Oricorio: 266-314 (91.4 - 107.9%) -- 50% chance to OHKO (better than I thought, actually)
0 SpA Gholdengo Power Gem vs. 0 HP / 4 SpD Oricorio: 392-464 (134.7 - 159.4%) -- guaranteed OHKO (I have personally not been able to fit Power Gem onto my defensive Gholdengo sets, but...)
And that's if you're dummy enough to attack slower Gholdengo first. Quiver Dance in Gholdengo's face and the only Shadow Ball you need to fear is the Tera Ghost Choice Specs one:
252+ SpA Choice Specs Gholdengo Shadow Ball vs. +1 0 HP / 0 SpD Oricorio: 195-231 (67 - 79.3%) -- guaranteed 2HKO
252+ SpA Choice Specs Tera Ghost Gholdengo Shadow Ball vs. +1 0 HP / 0 SpD Oricorio: 260-308 (89.3 - 105.8%) -- 37.5% chance to OHKO
252 SpA Choice Specs Tera Ghost Gholdengo Shadow Ball vs. +1 0 HP / 0 SpD Oricorio: 238-282 (81.7 - 96.9%) -- guaranteed 2HKO
252+ SpA Choice Specs Gholdengo Thunderbolt vs. +1 0 HP / 0 SpD Oricorio: 294-348 (101 - 119.5%) -- guaranteed OHKO
Admittedly, you can't OHKO Scarf Tera Ghost(/Fairy) Gholdengo back with a +1 special attack:
+1 252 SpA Oricorio Hurricane vs. 0 HP / 0 SpD Tera Ghost Gholdengo: 240-283 (76.1 - 89.8%) -- guaranteed 2HKO
Tera Electric makes Oricorio-Baile turn into a non-Flying Oricorio-Pom-Pom instead. More importantly, it gains a resistance to Electric and neutralities to Water and Rock while not leaving it open to any more priority moves.
Let's compare this Oricorio-Baile to defensive Talonflame sets I've seen floating around for how well they tank Gholdengo's attacks and scare out Gholdengo:
252+ SpA Gholdengo Thunderbolt vs. 248 HP / 0 SpD Talonflame: 298-352 (83 - 98%) -- guaranteed 2HKO
52 SpA Talonflame Overheat vs. 0 HP / 0 SpD Gholdengo: 254-300 (80.6 - 95.2%) -- 12.5% chance to OHKO after Stealth Rock
0 SpA Talonflame Overheat over 2 turns vs. 0 HP / 4 SpD Gholdengo: 352-418 (111.7 - 132.6%) -- guaranteed KO in 2 turns
52 SpA Talonflame Overheat over 2 turns vs. 252 HP / 4 SpD Gholdengo: 380-450 (100.5 - 119%) -- guaranteed KO in 2 turns
0 Atk Talonflame Flare Blitz vs. 0 HP / 0 Def Gholdengo: 228-270 (72.3 - 85.7%) -- guaranteed 2HKO after Stealth Rock (20.9 - 24.8% recoil damage)
A bulkier Oricorio EV spread of 116 SpA / 140 SpD / 252 Spe Timid dodges the OHKO from Modest Gholdengo Thunderbolt and Modest Choice Specs Gholdengo Shadow Ball but fails to guaranteed OHKO max. HP Great Tusk with Hurricane. A similar bulkier Oricorio spread of 192 SpA / 64 SpD / 252 Spe Timid dodges the OHKO from Timid Gholdengo Thunderbolt and now guaranteed OHKOs max. HP Great Tusk with Hurricane but always fails to OHKO 0 HP / 4 SpD Gholdengo with unboosted Revelation Dance after Stealth Rock and fails to guaranteed OHKO no-bulk Iron Treads with unboosted Revelation Dance.
Actually, rather like Quaquaval, Oricorio-Baile tends to end up being a sweeper first and a hazard remover second, but insurance always feels nice!
These are admittedly not high-ladder, and they all have Oricorio come with Orthworm support (Orthworm lures Fire and Fighting attacks/attackers quite well, including Corviknight and Great Tusk, and can Shed Tail), but here are some replays featuring Oricorio-Baile: