We used to get the name of a family that "fell through the cracks" for Christmas. My kids were told that if you would not want to get that item as a present, you do not give it to someone else.you have to be very, very careful when offering anything.
i would recommend going through a church or organization and not offer directly to a person you don't know well.
i learned that a local family ... in very dire straits ... was insulted by things being donated to them (torn and dirty things) and put them out with the trash. i did not see the items, but the feeling was 'if it's not good enough for you, why would you give it to me?'
one man's trash is another man's treasure ... it's so hard to know which.
and i believe stained bed linens would be discarded by goodwill, not sold. check first, but they'd probably only take the cases and top sheet. having shopped there, i have never seen stained clothing or sheets..