Shout Wipe & Go Instant Stain Remover Wipes, No Wash Required, Safe on Colorfast Washables, Travel & Baby Diaper Bag Essentials, Removes Grass, Coffee, Makeup & More, 12 Wipes (Pack of 6)

I am also a fan of white clothes and traveled with a Tide pen for years, but I find the Shout wipes much more effective. They make very packable singles, so I carry one in my travel wallet to treat stains as quickly as possible.