SWIM and his friends all use either ammonia or sodium carbonate for A/B extractions and they all get great yields with those. Both of those can bring a solution up to pH 11. That's plenty enough for all A/B extractions. After two friends of SWIM ended up in jail after being reported for purchasing sodium hydroxide, none of SWIM's friends use that anymore. Sodium hydroxide is good for STB techs, but not needed at all for normal A/B extractions. Sodium carbonate is sold in some local stores as "washing soda". It can also be made by baking sodium bicarbonate (common baking soda) in the oven. Another base commonly used for extracting from Yopo is calcium hydroxide (sold as pickling lime). This is a very strong base. It can bring a solution up to pH 12.4 and can be used in an STB tech, but you need to soak a little longer, that's all.