Hun, why not just empty out half the capsule of SB to give to Ava (and the same for Kato), since you'll have empty capsules arriving so you can use the powder you emptied out?
As to the couch cleaning, do you have cushions on the couch that can be removed? I pulled the cushions, took them outside, generally doused the area with the enzyme cleaner, and let them sit for about half an hour. I squished out what I could, and let them dry in the sun. It still took about three dousings/dryings. The problem is that urine wicks - so until you get enough enzyme cleaner to all the places the pee went, the problem doesn't resolve. If you don't have cushions that can be removed... it'll take a lot longer.
As to the couch cleaning, do you have cushions on the couch that can be removed? I pulled the cushions, took them outside, generally doused the area with the enzyme cleaner, and let them sit for about half an hour. I squished out what I could, and let them dry in the sun. It still took about three dousings/dryings. The problem is that urine wicks - so until you get enough enzyme cleaner to all the places the pee went, the problem doesn't resolve. If you don't have cushions that can be removed... it'll take a lot longer.