How to Drink Sea Buckthorn Juice? Make the juice by mixing the water before drinking the juice concentrate. A typical dilution is one part of seed buckthorn concentrate to five to seven parts of water. It can also be used to give a more satisfying flavor when used in the direction indicated by the producer. You can mix it with fresh juice, smoothies, warm water or honey water mix. Just make sure you mix everything well and follow the directions on the product.