Variously called Death Day, Decision day, and a number of other less kind words, D-Day was the day that the Allies began the big push from the coast of France all the way to the heart of Germany, ending WWII.
More importantly when it comes to cystic acne, tea tree oil can be harmful to your skin when applied in high concentrations. Some individuals have reported severe skin irritation and allergic dermatitis after applying too much tea tree oil, or applying the proper dose too frequently.
Using tea tree oil at full strength can cause skin irritation, which is why it is often diluted with other natural ingredients, like raw honey or coconut oil. Different treatment options also call for different percentages of tea tree oil. For example, acne treatments only require 5 to 15 percent TTO.