I have so many questions.... However, I'll make a suggestion instead. Go to the hardware store and buy a couple of buckets to fill instead of the bottles. Should be able to get a few flushes out per bucket and it will be easier. The biggest question I have is why has this water leak not been repaired in so long that there is an alternative toilet flushing protocol. Most places would just ask a neighboring business for access to their restrooms if it was only going to be a day or two.