Interesting - What effect do you find using two retainers has over using just one? Are they of different sizes as per some of TetherSpouts experiments? I think I could probably thread and unthread the retainer on the spout if I didn't find the process somewhat erotic with the inevitable consequences! I especially find the slight sensation of the spout sliding through the retainer has a bit of the "lock clicking shut" appeal about it. Using enough of the right lube seems to make a big difference - one of those situations where a very slippy water-based lube is better than silicone I find.