Bring 2 cups water, garlic, and 1 teaspoon sea salt to a boil in a 1 1/2-quart saucepan, then drain in a colander. Blanch garlic in same manner 2 more times. Dry pan well with paper towels, then add garlic and cover with duck fat. Simmer, uncovered, until garlic is very tender, about 5 minutes. Drain garlic in a sieve set over a bowl, reserving fat, and purée garlic in a food processor to make confit. Cool completely before putting in cavities of
squabs.