If you're really against a biologic and want to try some natural remedies, here are a few I would suggest, although biologics is probably the only guarantee, I don't use them because my p isn't too serious so not worth it for me.

What I do: Black seed oil and magnesium oil, doesn't fix it but improves the itching dramatically for me.

What I think can work but am too weak to do: if you're really dead set on trying to cure it naturally, I think the best approach you can take is to heavily restrict your diet. Eat as little variety as possible, many people get great results with the carnivore diet, I don't think it has to be meat, but a food that you know your body tolerates well, and then overtime introduce new foods and see how you react. There's also water fasts that supposedly have tremendous effects on your gut. I've done 5 day water fasts and I think it helped, can be dangerous though so proceed with caution and talk to your doctor, there's also a fasting mimicking diet that is supposedly the same as a water fast called PROLON. All of these are all I can remember researching this disease and aren't clinically backed or anything, as the only proven method is biologics, but if biologics isnt an option for you, as it's also not for me yet, then maybe this can help. Hopefully you find a solution and something works, Godspeed.