Mix the cucumbers and sea salt together in a bowl, let stand for 30 minutes to let the cucumbers soften.
Drain, and rinse with fresh water.
While the cucumbers are standing in salt, whisk together the sugar, vinegar, and water in a saucepan; bring to a boil. Reduce heat, and stir in the chili bean sauce and hot chili oil.
Mix the cucumbers with sliced chiles, onion, and garlic in a heatproof airtight container, and pour the hot vinegar mixture over the vegetables. Cover and refrigerate for 2 to 3 hours to blend the flavors.