One other thing you might try, but it can be HAZARDOUS. You will need heavy leather gloves, long sleeves and some safety glasses.
Try holding the mold up tight to the pot nipple, it usually fits right in the pour hole. When you pour, the cavity will fill and so will the pour hole. This is where sometimes you get a slight splatter and where the safety gear comes into play. It acts kind of like an injector. NOT TO BE DONE WITHOUT PROTECTION.
TJ