A. Yes, as a foliar spray. For those not knowing calamondin, it is sometimes called calamonsi in the Philippines. It is a citrus similar to a small lime.
You would waste your money applying it to the soil unless the soil pH is about neutral (7). I looked at the label. Dilution, use distilled or RO water and apply with a spray bottle. Because it has Yucca extract in it you should not need a wetting agent to get it inside the leaves. Repeat sprays weekly. Might take 3 to 4 applications to see results but each spray it should get darker. Do not use tap water if the pH of the water is too high for this product. You need a pH of about 7 or lower for this to work right.