Get a free sample of Crest 3D Whitestrips from Walmart. Look for the blue “Sample Whitestrips” tab at the far right of the page, then click on the “Request Sample” button at the bottom of the page to get to the form to fill out. This sample has been restocked so go ask for it if you missed it previously! You should receive your sample within 4 weeks.
Find all the Walmart samples here.