urine odor remover

How do i get cat urine smell out of carpet?
We just moved in to a rental house and it smells like cat urine. I have rug doctored and sprayed pet odor removers. Nothing seems to be helping.. if anything the smell seems worse than ever. Is there any products that seem to work on removing cat urine odor?
Use listerine or any brand of mouth wash.Just dont use the “blue” kind cuz it will stain carpets. I use the Equate(walmart) brand It really works. I used it in my steamcleaner and got that horrible smell out of my carpets. The people who lived in our house before let their cat use every corner of the house as his personal urinal. It took 2 applications..but the smell came out.