I've been cooking up rocks from high quality coke using baking soda and getting back 0.7g per g but when smoking it does nothing but keeps me awake. I do 0.05g from a glass tube hold it for 20secs and blow out loads of smoke.
Seems pretty straight forward to smoke but is the problem with the cook (too much water and too much baking soda?) or smoking technique (overheating underdosing)?
Does the baking soda method just suck and I should use ammonia?
Use ammonia. Also, do breathing exercises first before you inhale to regulate your breathing (you'll be able to hold your breath longer/make sure to full exhale and then take a but in a chillum pipe, trust me, normal pipes suck in comparison, you don't nee to turn the pipe as it's narrow - it's better for many reasons). When you exhale, there should be no smoke, otherwise you've wasted it.
Then, sit down, and when you're about to breathe out stand up and exhale really fast.
The technique behind smoking it can make it 5x more effective if you don't right.
Chillum pipes work the best. Use gauze, ash, crack and then ash again, then gently pat it down with a cig but. With chillum pipes, if you don't manage to smoke it all, the crack gets stuck in the ash and you can keep smoking it, none of it gets lost as it solidifies in the ash and the vapour cannot escape.
(Personally, I hold it in for 2-3 mins and sometimes so two different rocks in the process - then sit down and stand up fast to exhale at the end, hits you like a train, if it's good stuff especially).