The story goes that Jack Daniels, who was diabetic, was waiting for his accountant and kicked his safe out of frustration. He ended up with a toe infection which ultimately spread to his blood and killed him. The joke that they tell around the distillery is that if he soaked his foot in his own whiskey, it may have killed the infection and saved his life.
A diabetic foot infection today can often be managed with antibiotics, a luxury not available in the early 1900's. Even so, these infections can still be deadly. People with diabetes have a decreased capacity to heal and what would be a simple infection can quickly get out of control.
A diabetic foot infection, when not addressed quickly can spread to the bone. A bone infection will take an extended course of antibiotics, often by IV, and the infection may persist. At that point foot surgery to remove infeced bone may be necessary to remove the infected bone. Amputation is even a very real possibility.
If you are diabetic and injured your foot, treat it like the emergency it is. Contact Houston podiatrist Dr. Andrew Schneider and say "I'm diabetic and I have a problem" and we will get you in the same day. But please, don't soak your foot in whiskey!