To purge eggplant without using microwave, preheat the oven to 375°F (190°C). Line a rimmed baking sheet with a double layer of paper towels. Shingle the eggplant slices on top of the towels and top with another double layer of paper towels. Place a second rimmed baking sheet on top. Bake until eggplant slices are easily compressed, about 30 minutes. Remove from oven. Working one slice at a time, press between paper towels until compressed. Continue with step 3.