How do you remove "mystery" stains from white clothing? They are yellowish stains. I have tried stain remover, rinsing from the back of the stain, and hanging in sunlight. Any suggestions or techniques?

Looks like someone beat me to the punch on OXY-CLEAN. The stuff works, we've never had a problem.

I would try bleach, if the garment is entirely white. If not, you could try spot-treating the stain with bleach by tying the section off with a rubber band, dabbing it with bleach, letting it sit for 5 minutes, and then rinsing the area off.

Are they bleach marks? If bleach gets onto clothes then it often leaves a yellowish stain which won't come out, no matter what you use. The only option is to dye the fabric if that's happened.

The stain could be a result of your water. Especially if you get your water from a well. It could be from body oils much like ring around the collar. Especially if the stain is in the armpit area. If you think it might be your water suppply affecting your whites apply a paste of Cream of Tartar ( from the spice aisle ) mixed with hot water to the stain. Let the clothing sit for at least an hour and launder in the hottest water possible. If you think it might be perspiration OxyClean is your friend. I make a strong solution of OxyClean with warm water and let the clothing soak for a few hours ( overnight is best ) then launder as usual. To help prevent these type stains always launder your whites the minute you take them off. Tossing them in the hamper while waiting for a full load of laundry allows the staining process to begin. If you can't toss them in the washer then handwash in Woolite, plain shampoo or Dawn dishwashing liquid. No more discoloration from sweat/body oils :)

First of all go see if you have chlamydia or something of that matter you can very possible have the drips or you need to learn how to wipe your behind but after that just use a lot of bleach.

i have the same issue, its not bleach as i cannot use it im allergic. i suspect its rust from the washing machine as ours is really old. sorry i cant help you get rid of them, thats why i am here too, but thought the stain cause may help...