I would argue to just leave it as "other" Sites have done
Sticky: Alternators, Free Energy, Perpetual Motion, Over Unity, HHO, pseudo science and all that...
No need to belittle too much I am always entertained by HHO, also some of the illegit devices create a fuel economy increase due to other reasons like modding your ECU (or an efie) which also seems to fall is psuido science even though they are pretty sound in what they do (though some dislike lean burn on non-lean burn vehicles)
I would love a step by step ECU modding discussion, sadly it typically enters legal juridiction on the software side
Also I think learning by doing sometimes is what is need for some individuals and showing them good protocal to test their strange mods isn't really a bad thing either.