I don't want to buy apple juice solely for this recipe. Is there a substitute that would work moderately well in this recipe? Perhaps a few tablespoons of vinegar? I never heard of apple juice marinade being effective what with the low acid content. The particular requirement in this recipe for cornish hens reads: "Marinate 6 hours-overnight with a cup or so of apple juice and salt, cinnamon, cumin, onion and a little paprika (all to taste)"