Clean the radish by scraping off the dirty surface and cut off the tail. Keep the green leafy stem part is attached to the radish. Cut the white part of radish in half of quarter if they are too big. Rinse them well.
In a large shallow bowl on in a kitchen sink, place the radishes and sprinkle with sea salt evenly all over. Let them soak for 2 hours, turning once or twice. When the radishes seem wilted and lifeless, rinse in a water a couple of times and drain in a colander. Let them sit while you are getting the filling ready.
Meanwhile, in a small pot, combine dried pollock or anchovies with 2 cups of water and bring to boil, simmer for 5 minutes. Strain to reserve 3/4 cup + 2 tablespoon of stock. Discard the fish.
In a small pot, combine 3/4 cup of reserved stock with 2 tablespoon of sweet rice flour. Bring them to med-high heat to boil and thicken, whisking constantly. This is the sweet rice paste (You will only use 1/2 cup of this paste). Let it cool.
In a blender, combine onion, apple, garlic, ginger, salted shrimps (if using), with the reserve 2 tablespoon of fish stock. Puree them until very smooth. Transfer the mixture to a mixing bowl, add 1/2 cup of the reserved sweet rice glue, Korean chili flakes, anchovy sauce, and sugar. Mix well and let it sit for 10 minutes for the chili flakes to soften up.
In a large shallow mixing bowl or a baking pan, place the radishes and smother with the chili mixture. You might need to do this in batches to avoid overflowing. Toss, rub and incorporate the chili mixture to evenly coat the radishes and its leafy stems.
Store the radish kimchi in a airtight container and let it sit on the room temperature for 2 days first, then store in the refrigerator for 5 more days. Your bachelor kimchi should be ready to eat. (Toss the kimchi with the kimchi juice on the bottom)