I like his idea better too. His problem will be that females are more territorial than males and he needs all three to be excepting of each other.
The idea behind the lemon water is the hope that it will confuse the two bonded chinchillas into not being able to tell their cage mate from the new guy. The hope is that they will then accept everyone. The negative side is that first, the smell would need to be very strong to mask their own scent, and second, on occasion they will turn on the new chin AND each other because they know someone doesn't belong and can't tell who. I have never tried this method myself. I have talked with other people who have and it has had mixed results.
The idea behind the small box is that they are so cramped they can't get at each other to do a lot of damage. I've also heard variations where the put the box in the car and go for a drive so the chinchillas are too busy being nervous of the changes that they don't think about fighting. Again, I haven't used this method but I have heard both good and bad experiences from others.
I have always only used the side-by-side cage method and the switching cage method, along with introduction in a neutral cage or play area that everyone is new to. I usually add a ton of tunnels and boxes that only fit one chinchilla so there are plenty of escape safe areas for them if they feel threatened. I also watch them like a hawk during introductions. Its also not a bad idea to have a glove or towel in case they hook up in a fight. If you go in with bare hands to break it up yo could get a nasty bite.
I should also metion that I have only ever paired two girls or one girl and one boy. Never multiple girls. You should contact Debbie.nl.ca on the forums. She breeds in small groups and has a lot of experience in getting multiple girls together.
