You could try the dettol washing liquid designed for clothes. I'm not certain how good that will be but to be honest it's got to be better for a carpet than urine. Another thought would be to get a non slip easy clean floor put down and the carpet taken up.
And also you can visit here:
Carpet...
Hello,
I use a carpet cleaner named CIF. It's a chemical cleaner but not so hard that damages your carpet. I use it from almost last 6 months. The cleaner is so effective and available at every store or super market. I think you should try this.....