Combine bacon and oil in a large saucepan over medium heat. Cook, stirring often, until fat is drawn out of bacon, 4 minutes. Add onion and cook, stirring, until softened, 4 minutes. Add flour and cook, stirring, for 2 minutes. Pour in clam juice and bring to a boil, stirring well.
Add milk, potato, clams and hot sauce. Season with salt. Increase heat to medium-high and bring to a boil. Reduce heat and simmer until potatoes are fork-tender, 10 to 12 minutes.
Ladle chowder into cups or bowls, sprinkle with parsley and serve hot.