Yes, I used a tiny amount of electrolytes (a product intended for large animals, and according to its package, it's largely sodium). I didn't use any of the commercial bee-food products because I wanted to steer clear of anything that might increase the need for cleansing flights in this bitter cold winter. (Particularly so early on because I had recently moved the hives and I didn't really want them to go out for as long as possible. I was hoping for a few weeks of cold to encourage them to forget about their old stand - and we all got a few months of cold weather instead. The bees did pretty much reorient successfully when they finally went back out after three months.)
I'm not sure if the bricks could be made in a candy board mostly because the bricks are dehydrated either in a proper dehydrator, or in an oven at low temps with door cracked open. (I haven't personally tried the oven method as I have an old countertop convection oven/dehydrator that I'm using for this.) The weak link in the plan would be the candy board itself, I think. After I've mixed the stuff up (which I do a in 5-gallon pail, with my bare hands) I scoop it into those lightweight aluminum foil trays that are sold in the grocery store for cake pans or brownies. They are then dehydrated for 6 to 8 hours, until they are quite firm. I just leave them in the pans until I install them in the hives. Next year I will buy some heavy-duty quarter sheets or brownie pans instead of using the flimsy foil ones, which can create cracking problems if you have to move them before they are fully dry.
I just set the bricks on the top bars within a shallow shim (@2" high) that also has my upper entrance hole. Above the shim is the quilt box - the bees sometimes fill nearly the whole volume of this space over, under, and many layers upon the brick chunks. When you look into the entrance hole, all you can see is solid BEES! In fact that's how I know it's time to restock, when a flashlight shining in reveals empty space.
Lauri's recipe and method of making them are brilliant, IMO. And my bugs think they are fantastic.
Enj.