Why in blazes are we calling these things funnels? You know, the adventures where you take a bunch of utterly unqualified characters and shove them through a dangerous situation until most of them die (often hilariously) and then the survivors get to be real PCs from then on? Essentially a winnowing process for aspiring adventurers, most popular in the more DCC-flavored parts of the OSR community.
That's not how a funnel works. If I pour thirty ounces of a substance into my funnel I'd better get thirty ounces out of it, not four with rest being eaten by monsters. It's not even a meat grinder, where I still expect to get about two pounds of ground beef out if I shove two pounds of chuck in. The terminology is all wrong.
This is really alluvial mining here. You're panning for player characters. The dungeon isn't a funnel, it's a mining sluice, disposing of the hopeless sand and unlucky gravel and leaving you a precious handful of viable PCs. It's just using the blood of its victims instead of water to do the job, which is a mental image I'm sure funnel-lovers would appreciate.
So no more funnels. Let's start seeing modules like "Blood Sluice of the Gore Mages" and debates about whether sluices are a terrible idea or not and whether the whole concept is truly Old School or modern parody based on faux nostalgia.
