If you REALLY want some TEC stop by the local chevy dealer and offer a mechanic $20 if he can find an old bottle around the shop. A lot of dealers have lots of old stuff laying around if they have been in biz for a while.
Agree, I tossed all my TEC, new and old a few years ago. If memory serves me correctly, and it doesn't always(blame using TEC), the formula was changed in the late 80's or early 90's, for EPA or health issues, maybe both I would guess. At one time TEC could only be had in 2oz plastic bottles here in CA.
I don't think steam cleaning will be the answer, hope I am wrong. Different dynamic with steam cleaning compared to turning water into steam during combustion.
Now here is the challenge. If a powder or chemical company could produce a propellant that could be loaded just like smokeless powder and it removed carbon, then when you are done shooting, you fire a few of these cleaning rounds down the barrel and it starts the carbon removal process, then you clean as normal and no carbon. Until then it's just going to have to be scrubbed out with what ever product you personally feel is magic.