Yup! I would wash them at least three times on hot before using, especially the hemp ones. <img alt="" class="inlineimg" src="http://www.mothering.com/discussions/images/smilies/smile.gif" style="border:0px solid;" title="smile">
I have some arbitrary numbers for prewashes for new diapers-4 for most diapers, around 6 for unbleached cottons and around 8 for hemp...this is for the diapers to be maximally absorbent for the first wearing. I wouldn't think you'd need detergent each time so much as you need the hot water (and dryer heat too) to break them in and remove natural oils in them. You can even boil diapers to speed up the breaking in process. A lot of diapers cannot have natural detergents and the such, so tide may have been suggested as a good all around detergent, but not necessarily the only one that can be used. When I'm breaking in new diapers, I often just throw them in with other loads instead of doing loads for new diapers only, so the wash may not be on hot.
I always wash new diapers a few times. It really fluffs them up and increases absorbency (IME anyway)<br><br>
However, if its a WAHM dipe, before you wash, check it over and make sure its something you want to keep, is free of defects, and that it will fit. Most WAHMs will not accept returns on washed/worn diapers unless they are very clearly defective.