The compressed stuff isn't totally dry, at least not the bales I've got. I don't think I'd be able to breath doing it if they weren't slightly moist. The containers are watered well after planting... very slowly and many, many, many times during the rest of the day until the water begins to trickle out. It takes time, but is easy enough to do between the harder chores, I consider it my break time. But I'm really not worried about leaving any dry mix at the bottom of the planters the way I'm doing it. I will burrow down really deep in one of the larger planters today though to check and be certain, I do appreciate that warning. I didn't think that much about it, but I really think the way I've been watering solves the issue.
Edit: I checked all the way down 1 of the 20" planters by hand and with my moisture probe and they are indeed wet all the way down. So the repeated slow waterings I'm doing right after planting seem to be working well for me.
