Found a Shiny! I used Sweet Scent to find some hordes while hanging around Route 14 (quick experience training) and noticed the fourth in a group of Bellsprout looking a little different from the others.
Now, it's notable how useless Bellsprout can be on its own. However, let me tell you something. If you don't have or use the moves that nail a group all at once (like I had to avoid using Bulldoze), those things can easily take down a Lv.100 Rhydon (mine was Lv.42). I was dealing with Poison Powder and Wrap taking out 36 HP at a minimum every single turn and had to quickly kill four, and was still hitting 36 damage per turn. I couldn't break up the Poison because I would get sprinkled again with that or falling asleep (and still Wrap to boot), and I couldn't attack the Shiny as Rhydon doesn't know False Swipe, and I didn't have another user with me (even if I did, it was impossible to switch because they took turns using Wrap).
After three heals and running out of basic PokéBalls, I finally let Rhydon faint. I found my lowest-level Pokémon on hand, a Lv.24 Poliwag that I just happened to catch earlier this evening directly northwest of my location on Route 14. I then discovered Hypnosis in its moves. That was enough for me.
Poliwag goes out. Immediately I get Wrapped again. Two Hypnosis attacks miss and I take Wrap damage. Bellsprout (Shiny one only by now) uses Sleep Powder. Thank goodness we can grow Berries again; a Chesto Berry was deployed. Immediately I'm put to sleep a second time with more Wrap damage (now 39/60). Another Chesto Berry was used, and Poison Powder was the response. HP dropped and I knew I didn't have much time to make Hypnosis work.
Thankfully, this time, Hypnosis connected and I chucked another Great Ball. Critical Capture. Shiny Bellsprout get!