Quick Dip is a product that you dip flower stems into immediately after cutting from dry pack. Flowers that have been boxed and shipped by a freight company should be processed (removed from the boxes, cut and placed into water) quickly.
An instant rehydrator is a product used by professional flower shops everywhere. They know that quick rehydration is the key to preventing droopy petals or stems.
Don't assume that because your online wedding flowers arrive limp that they are "dead". Flowers travel a great deal of distance from far away flower farms and are re-hydrated with great success.
I am more trustful of flowers shipped directly from a farm than those which are being sold at a greatly discounted price. Those types of flowers are purchased "box lots" that haven't been sold immediately when they arrived at a wholesaler outlet. They are then sold cheaply just to get rid of them. Most florists used these types of flowers for funeral work or other work that doesn't require the "staying power" of several days time.
I also believe there is greater danger of buying flowers that are in shopping or discount centers and displays - primarily because they have been removed from their travel boxes, cut and been sitting in water in a warm environment for several days. That is when you are in the most danger of receiving a flower that has a shorter shelf life.
Professional flower shops keep their flowers in a cool refrigeration unit specifically designed to keep flowers hydrated and immersed in clean water treated with flower food.
Although florists tend to buy Quick Dip in gallons or larger, I do provide a convenient 32 ounce bottle for brides. You simply do not need as large a container as a professional.