No Stupid Questions

Yay a question just for me. Okay so you're going to want to try a couple things. First give them a good spray of just regular Lysol or adjacent, the idea is first eliminating anything living that might grow back. The next is a product from Lincoln called EZ cleaner. Take the cleaner a few drops of a dish detergent and hot hot water and scrub it into every surface. Then take a rag to blot at the surface a bit. Once they are dry you're going to take a similarly stiff dry brush and brush them all over with the intent of both making them fuzzy again as well as freeing the dirt that has come to the surface during the cleaning process.

If that didn't work and it's probable it won't try a few more times. If that still won't work you might need new Birks or perhaps have a cobbler like me replace the footbeds if you are particularly attached

You probably don't. Those tummy acids are strong. I would wipe the surface with soap. Maybe submerge them in water if you can immediately place them in direct sunlight afterwards to dry them out again. Wipe surface again and hope for the best. I would water an un-vomited-upon Birk along with the offender, maybe not in the same sink water, to wear them out equally.

I just wipe it off and go over it with a little Simple Green

Generally, once it's dry, it's a permanent stain, and likely some deterioration of the materials. It won't be major damage, as in making them fragile, but they won't look nice.

Remove all visible matter, obviously

Get a bowl and an old toothbrush, along with some rags.

Laundry detergent, preferably without dyes or scents. Be aware, that the colors in some detergents will stain leather, and might the soles.

A few drops of white vinegar, a few of the detergent, and some warm water in the bowl. Dip the brush and scrub gently until as much of the more ingrained matter is gone, and you're no longer seeing the brush pick up anything that discolors the liquid. Now, in most shoes, that might never happen, so you might have to settle for it reaching the point where the colors of any stains are even. No telling unless I was there and doing the work; even pics wouldn't help.

Switch to plain water, and clean the brush well, so that you can use it to remove soap residue.

Use the rags to dry the shoes as much as possible once finished.

The next part is where you gotta buy stuff. You'll need a leather conditioner, and a cork sealant/conditioner if the cork was soiled. No way around it, no shortcuts because you're already going to be stripping some oils from the leather, so cheaping out makes no sense. But it can be the inexpensive stuff.

Also, don't use other kinds of soap. Laundry detergent is going to strip the least amount of oils.

You can maybe get by with bypassing all of that if only the leather is dirtied, and just buy some leather cleaner, but I can't say it works any better; it just takes less steps.

From there, air dry. You can use a blow drier on low heat if you want

For (genuine) leather, saddle soap or Renapur leather cleaner is probably your best option.

For non-animal-based materials an enzyme cleaner.

Worst case scenario, dye them black.

Get a dog. They'll clean it up.

Patchouli

why would you own shoes that can't get wet

Teach your cat how to wash it's vomit.

Oh! Mr Wiskers! Did you vomit on the carpet??? Go get the cleaning bucket!

Meow!

No, I don't care. You're cleaning this!

Meow!

Yeah, you're gonna think twice about doing this again, aren't you?

Meow!

Pssshhhh!!!! I'm not bailing you out. Now clean this up!