Vodka only has I think 40 to 50% alcohol so it would take much longer time and not extract as well. If the storage place is too cold, then that might also explain why it didn't work. Bacardi 151 has 75% and works a lot better. Everclear or lemon extract work even better. Also, decarboxylation of THCA is rarely mentioned in any of the green dragon recipes but it makes a huge difference in the strength of the green dragon. If the weed is fresh, then it needs to be dried thoroughly using a microwave or oven. When you smoke weed the flame instantly converts THCA to THC, but if you eat or drink THCA it will not get you high. Hope that helps. I understand your disappointment as I have done a lot of experiments to get it right. It sounds like Master Wu did a lot of experimenting too. The easiest way (I haven't tested this yet) is to probably use a microwave to dry the weed (less likely to accidentally vaporize the THC), then use lemon extract and store in a warm cupboard (Everclear is not available in some places).