Just try more heat man, what do you have to lose? The first time I was successful, it was because I thought I had ruined a gram+ of weed and said "F IT, I'm just putting it in the crockpot on high for four hours." This was after cooking for 3 hours on lower heat in the oven. I observed the crockpot temp going to 350 and hovering around 300. This means my oil was 250+ and you only hit 222. More heat.