Home Remedies?

Hello all,
I've read some of the threads here and you seem to know your cat stuff pretty good.
This is my problem: I recently moved into a new apartment, and near the front door, apparently to previous tenant's cat urinated or sprayed there. One of my cats, is peeing there now.
I have spent nearly $100 on cleaning supplies and Pet No-Go products, only to have him still pee there.

The other one, conversely has drawn an imaginary line near the area and won't cross it, will not go near the front door.

I have doused it three separate times with an Oxi-clean solution as well as other things from the pet store.
He hasn't behaved this way before, and nothing traumatic has happened to cause him to act out.

My question is this: Are there any home remedies that will put a stop to this until I can get the carpet (hopefully) replaced by the landlord?

Baking soda? Herbal something or other? Cayenne pepper? Eye of newt?

J - Welcome to the catsite. I have used a product called Nok-Out very successfully in removieng odors like cat urine. I learned about it here - and bought it over the internet. Arrived in a day!
www.kalever.com

Thanks, I looked up the site, and ordered a bottle of it.
And pass the word that Oxi-Clean does NOT work for this problem.

J - I hope you will have the same success I had with the Nok-Out!