Use spinach water for removing sweat stains and ring around the collar. Try blanching fresh spinach. Reserve the water for stain removal.
It doesn't matter if the water is hot or cool. The green water has some type of iron element in which works on the stains. I guess it is the same iron oxide used in antiperspirants.
Swab it on with a toothbrush. It sometimes take out the stains that nothing else would. It is safe for almost any kind of fabric.
Login using the form on the top of the page to post feedback (if you are a registered user). If you have not yet registered, click here to do so. It's FREE!.