Couple tricks you've probably heard before, but someone might not have...
Dr. Tims one and only actually works (instant cycle). I have used it with no ammonia. I've also used stability which seems to work but the one and only seems a little better, and I've gotten bacterial bloom with stability before. Not a big deal but you have to watch your O2.
I wouldn't throw 5 big tangs in, but for a hospital or QT, they work pretty good in a pinch.
I also keep a sponge in my display sump which I can drop into a QT tank.