Car Interior Cleaning

I have completely gutted the interior of my car, cleaned everything up, new carpet, and am now putting it all back in. I am curious about seats. I have cloth seats and vacuuming them and shampooing them doesn't seem to take the "OLD" smell out. Can seats be soaked in a detergent like OXY clean or similar, or will this cause more problems than its worth due to the padding soaking up the water...

I have completely gutted the interior of my car, cleaned everything up, new carpet, and am now putting it all back in. I am curious about seats. I have cloth seats and vacuuming them and shampooing them doesn't seem to take the "OLD" smell out. Can seats be soaked in a detergent like OXY clean or similar, or will this cause more problems than its worth due to the padding soaking up the water...

if your up to it , take the seat foam out . wash with a little bleach and laundry soap mixed in a large bucket/5 gal pail ..dry very thoughly then use a wet vac with carpet shampoo and odor remover applied to clean the cloth material..