I was told to use tea tree oil and water solution and not harsh detergents because my yoga mat is biodegradable (I was warned to keep it out of the sunlight). High maintenance yoga mat! 
Seems like it would be a good bet though since it's is anti-bacterial and all that good stuff.
I've also read that you can put it in the bath tub w/ detergent and scrub it if it is super dirty.
"Live, more than your neighbors. Unleash yourself upon the world and go places. Go now! Giggle. Know. Laugh. And bark the the moon like the wild dog that you are!" - Jon Blais