Our long period of potty training is still ongoing, and at the moment, a lot of underwear it falling victim to that.
After washing by hand with clear water and washing in the washing machine at 60 °C, there still remain brown stains in many of the (colored) pants.
What is a good way to get rid of those stains?
There was a similar question about cloth diapers How do you remove stains from cloth diapers?, but sunning is not an option during fall and winter and bleaching in general does not work well with colored clothes, I suppose.
(Should somebody propose to just trash the stained underwear, this is not acceptable for us, as is is not only a question of cost but also a waste of ressources, especially as we need really many of them at the moment - sometimes 1..5 per day)