That defeats the purpose of the button then. The Dash is supposed to prevent you from having to pull out your phone to order things. For example, you notice your detergent getting low, you notice the Tide Dash button right in front of you, you push the button and voila, 2 days later your next box of Tide is on your door step.
True, I guess I imagined it more as building a shopping list throughout the day/week and ordering once at the end of the day, not separate orders for every button click.
Maybe have one generic button that opens an app on your phone to choose an item from your 'frequently purchased' items.