Misc Dose of instant kava for an alcohol-like buzz?

[Troppo]

I'm trying instant kava as a way of reducing my alcohol use. I first tried a brand that is cheaply available in the local supermarket here in Australia. It was supposedly Fijian noble kava but it did next to nothing, even at a dose of 20 grams in water, taken at least 3 hours after eating. I then ordered some Vanuatu instant kava for a higher price and it did work, at least to some extent. 20 grams in water gave me the classic numbed mouth and burning taste (3 hours after eating) and had an alcohol-like effect but it only lasted for one hour. I need something that will last at least 2-3 hours, so I can take it before bed and enjoy watching TV for a while until I'm ready for bed. I eat at 5 p.m. so I reason that if I move my dinner time to 4 p.m. I should be able to take the kava at around 7-7.30. I'm just wondering what dose of instant kava others find effective in producing an intoxicant effect, and how long that effect lasts.