I’m going to give you the best advice I can give. I have not experienced this personally but I’ve read a little about it.
1. Get an opinion from multiple vets not just one. Some veterinarians have more training in that area than others and some have better meds.
2. Start feeding your cat chicken baby food with rice it will be better for his intestines and less painful.
3.once you found a vet or you decide to stay with what ever vet ask them to retest for parasites. Sounds like he could have possible hookworms even though it’s uncommon he may have it on top of the toxin.
4. Get pedilite or something to help boost your cats electrolytes this is important because with that much diareah he could loose too much fluids.
5. Write down everything you cat does and what time so your vet knows what is going on. Include pee time, color and look of diareah, color of gums, his activity, his pain level, his playfulness. Everything he does while you are there.
And I can’t stress enough call multiple vets and explain what is happening and what is not working okay? Blessed be honey keep us updated.
a wet washcloth is usually a good weapon against soap… 🙂
Do you think his walking around outside would be enough, or definitely not?
if it doesnt come off from grass wash it off its not like its gonna burn his or her paw just dont let him lick it