FREE: Smoothie at White Castle 5/24 May 21, 2015 By: Tricie share Head over to White Castle this Sunday 5/24 and grab a FREE 10 oz. Smoothie with this Coupon. *Limit one coupon per customer per visit. Find a location near you by clicking here. See more FREEBIE deals HERE! Please be advised that this post may contain affiliate links. See my Disclosure Policy for details.