Yes wash all clothes before your LO wears them and we use any free & clear detergent because I don't like the perfumes in Dreft, and you never know if your LO may have sensitive skin.
I posted this a few days ago and majority said yes, wash them. apparently they can have chemicals and things on them. I'm using sensitive tide for washing baby clothes since I already use it on my own delicates and it's scent and dye free.
Yes wash things, but hold off on washing EVERYTHING. I've heard from many mothers how they washed all their stuff and their baby was either born large or grew fast so they never got a chance to wear them or return them. Specifically I've heard this about onesies. Good luck!
Re: Baby Clothes
Many baby specific detergents still have dyes/scents in them. I would recommend a free and clear to avoid reactions.