Well, in the end I decided to skip whatever this weekend's cheesemaking disaster was destined to become, and instead only made the laundry detergent.
The entire process took, umm, three minutes, and that included a time-out to make myself another cup of tea. Could NOT be easier. Now mind you, I haven't washed a load of clothes with it yet (that's tomorrow) so I am reserving judgement on the whole thing for another 18 hours or so. But if it works, and I have no reason to think it won't, I will post the recipe here tomorrow.
Oh please let this work.