In a large blender, add the oats, maple syrup, vanilla and salt. Cover with the ice water.
Blend for 30 seconds max (this is the most important part!) Over-blending will lead to a slimy texture, plus 30 seconds will be plenty of time!
Immediately strain through a cheesecloth. I've found a cheesecloth is the best straining tool, a normal strainer will let in too much meal and will lead to a grainy milk.
Use your hand to squeeze the milk through the strainer, do this step slowly to ensure you get all the milk out.
Chill in the fridge and use as-needed. This will make 24 ounces and last for up to 4 days!