Our carpet at our previous house was a horrible carpet that held onto stains and it showed up every tiny little bit of dirt. I thought it would be almost impossible to clean the grot from 4 kids when we left but amazingly we found a brilliant carpet cleaner who got every single little spot out of the carpets and it looked better than it did when we first moved in there. I say definitely look at getting someone in to clean it for you. I don't recommend the ones that dry clean though as I found they only took out the top layer of stains and left the rest underneath. Someone who does steam cleaning is the way to go - or just bug your DH until he finally does it