technically tinctures are made with alcohol, oils are made with oil.. To another part of what you said, I saw a video from a Canadian woman that puts her bud in the oven in sealed Mason jars. I think heating it for 4 hours is destroying a lot of the THC. There's a chart somewhere that shows how THC breaks down with heat and time, it shows that the optimum is like 240F for 90 minutes, any longer or hotter and the THC starts getting destroyed. I've also seen people infuse oil on the stove in a double boiler setup where you just put the bud in the jar with oil.
If you can afford it there's also something (I think) called a Bud Buddy or something like that that has a little blade in it that spins and chops up the bud in oil while heating it at the same time.