Soak the clothes once they are soiled before actual wash. The stains and smell will come off easily when still wet, hence easier to rid the sour smell.
warm water add few slices of lemon. soak it for 1hr. after that wash with normal water. then u can use baby detergent to wash as per normal
I wash my baby's clothes in warm water and soak in fabric conditioner. It takes away any odours.
Before washing the clothes, put some vinegar on the clothes. The vinegar takes away the smell.
After washing, Try to Rinse with some lemon juice and lime/mint leaves
use Lemon water and soak for half hour will prob helps
Add some lemon n soak it for some time before washing