Use hydrogen peroxide. Need a recipe? Mix together 1/2 cup of baking soda, 1/4 cup of hydrogen peroxide, and 1 tsp dish soap. Apply cleaning mixture onto the grout, wait...
No, because the pastry would defrost first, it would end up soaking up the filling and you would end up with a soggy base. Also, you would end up cooking...
Mix one tablespoon of lemon juice or vinegar with one scant cup of milk and let stand at room temperature for 5-10 minutes. The mixture will thicken into small curdled...