Free Sample of Crest 3D Whitestrips This post may contain affiliate links and I may be compensated for this post. Please read our disclosure policy here. January 10, 2011 Sharing is caring!0sharesShareTweetPin Walmart is offering a FREE sample of Crest 3D Whitestrips. Fill out the quick form & your sample will be on its way by mail in a few weeks. Thanks Coupon Geek!