Carpet Cleaning with results!

So today I searched the internet for the best DIY method to clean my carpets. A little background...we have our carpets cleaned every 6 months-a year, and low and behold the carpet is so dirty from the high amount of traffic between 5 kids, me and the hubby, and 3 Doxie Dogs. It's pretty much ruined but I did want to clean it to keep it sanitary the best I could till we can afford new carpet or wood floors.
First I tried the carpet cleaning solution from bissell...Results=Okay
You can see the left side is where I cleaned, with the assistance of a handheld Bissell machine...

Second I did the vinegar and water solution...Results=FAIL almost no difference at all (no pic)

Third was the Amonia and Hot water, which is 1 cup water per Tablespoon of Amonia..Results=Best
So I'm still looking for a better method to make my carpets look as new as possible.
Before picture...

 

After picture...