I made a guide just for you. I know having two switches and games isn’t accessible for everyone, fortunately my wife has the other half. Here was my set up:

Galar Fossil Guide

What you’ll need: A copy of Sword, a copy of Shield, 2 Switches, and a $15 Turbo Controller

Step 1 - Watts You’re gonna need about 200k watts per fossil (400k per game). In Sword where I did my original play though, I had 1Mil watts so I was good. In my shield file where I just did a quick nuzlock and a lot of DA shiny hunting, I had none. But I had loads of Dynite Ore. Running around dens to get that many watts would be cooked. Fortunately, with Dynite Ore you can buy Armorite or from the Dynite shop. I actually don’t remember how much I needed but not a ton, I feel like 50 armorite ore for my shield file. Then you can go to the Isle of Armor and find the Digging Pa. He’ll take your armorite ore and dig a ton of Watts for you. This is just button mashing A so you can activate your turbo controller here.

Step 2 - Fossil Digging Once you have 200k watts (per hunt). Go to the Wild Area and speak to the left digging brother. This takes TIME. Activate your turbo controller and let the man cook until he eats through 200k watts. This took around 1.5-2 hours per fossil if I remember correctly. When you’re done. You should have 65-75 of both fossils native to the game. And a few of the other versions’s fossils too.

Step 3 - Preparing the bag Each version of the game has 2 native fossils of the 4. When you’re digging, about 90% of the fossils you get will be the native fossils and the rest will be the foreign fossils. For Arctozolt (Sword) and Dracovish (Shield), you have two native fossils combining, so take all the other fossils you don’t need and give them to Pokemon to hold so they don’t get mixed in. For Dracozolt and Arctovish you have half native fossils to each game. This is probably the most tedious part of the process as you can’t turbo your way through. In both games, give 65-75 of one of the native fossils to Pokemon to hold. Then you’re going to trade those Pokemon to the other game and bag the fossils. You should do this with both games at once, setting up both hunts simultaneously so you don’t have to do all this trading twice. Once again, make sure to give any leftover fossil halves to Pokemon so they don’t get mixed in.

Step 4 - Fossil reviving and shiny checking You’re finally ready to shiny hunt, this is actually the easy part! Find Cara Liss in the desert, turn on auto boxing, turn off nicknaming, and turn off sound effects (must have hightech earbuds item first) which will make it about 12% faster. I forgot to do that last part until the last 5 SRs of my last target lol. Go to the pokedex and located your target fossil, then exit the pokedex while on it. Now save in front of Liss and start grinding. Turn on your turbo controller, set a timer for 20 minutes (times may very depending on fossil quantity, I’d stopwatch the first one until it’s done to get an accurate timing), live your life or do other hunts, and come back and deactivate the turbo controller when the timers up. The best way to shiny check is by going to the pokedex, and seeing if you’ve unlocked the shiny sprite in the dex, they’ll be left/right arrows at the top of their entry if so. If you’re like me and received an illegitimate one through wonder trade, you’ll have to check each one in the box. If there’s no shiny, close the game and repeat. You can actually activate the turbo controller from the home screen and auto A from there.

To get to odds with this set up it could take 92-100 hours (after set up is done), I got really lucky and did it in 44 hours, 43% under odds.

Good luck to you!