In large bowl, combine the sugar and salt in water and whisk until sugar dissolves. Add shrimp to brine solution and let sit for 30 minutes on the counter. Do not stir, just leave alone. Soak wooden skewers in water, in another container, for 30 minutes also.
Make the Chimichurri sauce; place the parsley and oregano, garlic, vinegar, crushed red pepper and olive oil in a small mixing bowl. Using a fork or whisk, stir to combine. Season with salt and pepper. Set aside.
Remove shrimp from brine, pat dry, and thread on skewers, 6 - 8 on each one, for a total for 3 or 4 skewers. Lightly salt shrimp and drizzle with a little bit of Chimichurri, not much, just a little to add some oil and flavor. Place on grill and cook 2 - 3 minutes a side, until just done and no longer pink.
Remove shrimp from grill, plate and drizzle with Chimichurri sauce. Serve, passing remaining Chimichurri on the side.