Thats the way to do it when you have the plip. The siren yapping is a nice reminder of the correct procedure.on mine after reconnecting the battery i simply set the lock and alarm on the plip and then unlock on the plip.That resequences the alarm.The lights will stop flashing in any event in 20 mins.
I have pulled the alarm fuse from my car when I have no working plip, reconnected the battery, and on pushing the fuse back in normal service has been resumed. Its annoying that they have so much other stuff on the same fuse that you can't just leave it out permanently.