Buttermilk-Substitute Waffles

We're headed back to the US for three weeks on Friday, which means I'm in the middle of a mad dash to get the laundry done and the perishables cleaned out of the fridge. Tonight's meal plan was waffles with blueberries, assortment of meats (chorizo, ham, and pork sausage), and melon. I wanted to do cornmeal since it combines so well with blueberries so I flipped through a recipe book to try out something interesting for the waffles and found a cornmeal and rye one in the Whole Grain King Arthur Book. I love this book so prepare for lots of adapted recipes from it.
The waffles were great but I didn't really follow the recipe. You see it called for 1.5 cups, 12 oz, of buttermilk and I have exactly 0 oz of buttermilk in the house. Instead I plopped the bowl on the scale and started throwing in a combination of ingredients I did have, and needed to get rid of.
The liquid ended up being a combination of greek yogurt, sour cream, a mushy banana, soy milk, and a splash of orange juice to bring it up to the required weight. I also had three egg whites left over from making hollandaise sauce, so I used those instead of the whole egg it called it. Since I was using sour cream and greek yogurt, I figured there was enough fat content to not screw me up to much, so used the called for 3 T of butter. I didn't have to adjust the dry ingredients at all; 1 cup cornmeal, 1/2 cup rye flour, 2 T sugar, 1/2 t baking soda, 1 t baking powder, and 1/2 t salt.
Husband: "Good waffles. Tastes like crispy cornbread."
Son: "Mmm, good! Pancakey!"