I?ve taken the No-Jet Lag pills. I've found that they work well unless you get woken up in the middle of the night. If you don't get woken then somehow they keep you asleep and there is no jet lag. But if you get woken (for example by a child who has jet-lag because she slept too much on the plane to take enough tablets or because a son comes home at 3:30 am and has forgotten his keys) then you can have problems getting back to sleep and so get the jet lag.
The only place I've been able to find them on sale in Hong Kong is in Wastons at the airport.