I think that you're right, DrewE. Simple is good, especially if I can still find AF on sale.
Not sure I can enjoy the idea of kitty litter. Might work for one thing, but the other would be nasty. then, how do you dispose of it? Naw, I think I'll go for the antifreeze.
Rock salt sounds interesting. It doesn't allow freezing? Could it damage anything in the plumbing? Hmmm. I'll have to research that one.
Thanks for the replies. I think my plan will be the simplest option, antifreeze. Rock salt sounds interesting and I'll keep that as a saved round and do some research. But for now it's AF.