Using a guilded altar is far more time efficient than using the ectofuntus. If you have any of the Morytania Legs then collecting the slime/crushed bones from Robin daily is more efficient, but that caps at 39 a day.
Also don't be hesitant to build a gilded altar in your own home versus using someone else's. It maybe cost several hundred gp, but it is still worth it and so much more convenient.
EDIT (Zant posted a bit before me): I agree with pretty much everything he said. Using a public altar does give the benefit of not having to light the burners, but I personally prefer being able to teleport in to my house rather than to the portal and entering every time. In the end that bit is just personal preference, I think using your own is still technically faster. His bit about using the action bar is very good too. I would say use the tokkul-zo over a dueling ring if you have it, but either one works really.
Although you save money with the Ectofunctus, the extra time you put into it is not worth the money saved, as it it singnificantly more time. The money you will make using the soul split and level 95 curses will completely overshoot the money that you will save with the ectofunctus.
This is spot on.
RSN: Parselmouth | Jaysawn on ********