I find a recipe in my Encyclopedia of Cooking by JoAnna Morris for aioli. Here it is: Remove the crusts from bread and soak in milk.

Squeeze dry. Place in large mortar with garlic & mash with pestle until a fine paste. Add the yolks & salt & mash in. Drop by drop pound in olive oil. When the sauce becomes thick; the remaining oil may be beaten in. Thin with water & lemon juice to taste.