Yeah, it's bulk but all I had to do was take the hygroton/ grow rocks out of my fruiting chamber that used to hold 16-20 cakes and fill it with shit. It takes up the same amount of space that it was taking up before, and now I don't use an aquarium heater or a pump for fresh air. Nothing needs to be plugged in so there aren't a bunch of extension cords running all over my house.
I think just growing on horse shit produces better shrooms in many ways, most obviously size, and number; maybe even a little more potent. They're also less prone to having hollow stems (big problem w/ my creepers) when grown on a more naturally nutritious substrate.
Of course you can mix the colonized grains with coco coir or other substrate to do smaller casings to put into a regular fruiting chamber with all the bells and whistles and humidifiers etc. Basically, if you have a PC, IMO, there's no reason to even keep those little pint jars around; throw them away and try grains.