Almost all new fabrics are sprayed with sizing and require an initial washing to remove it. That's what causes itching. Wash it first, your nethers will thank you for it.
I wash everything before I wear it. New stuff makes me itchy.
Are you really serious??? Of course you wash them first. You should wash anything new before wearing. Most packages will even tell you that. Beware of what is lerking inside of packages that you cannot see. Oh yeah you do wash your hands before eating right???
Well, actually no, being on a jobsite I don't always have the opportunity to wash my hands before eating. But being a plumber I usually put my gloves on before picking up my sandwich.
I don't generally wash 'em first. If there's anything to be "caught", I would have already gotten it when I tried them on in the store.
Goodwill?
If something comes in a package I usually do not, but a lot of girl stuff does not come in packages so I certainly wash first. Especially bras, you know people try those on at stores.