I like the freezing into pucks idea, for those things amenable to doing that.
To re-address the folding over the top of the bag approach, I believe I'm correct in saying that each time mentioned here, folks are saying "fold over the top toward the outside so an inch, say, of the inside now makes a rim facing out" (so a single fold) and the failure noted is that drippage/smearage can just as easily drip or smear on that "inside" (facing out) before even formally starting into the remaining bag (whose inside is still inside...) (where it also drips/smears, leading to the entire question).
Well, yes. But if you fold again, so now (using the inch fold over above) one has two inches at the top folded over with the first inch tucked up in between the second inch and the remainder of the bag.
Then drippage/smearage may very well happen on that inside-facing-out second inch as well as the remaining inside of the bag. But it won't happen (without a lot of help) to the first inch which is folded up to tuck between the second inch and the bag.
Protected like that, one would seldom see a problem just unfolding and sealing, but could though if careless in several ways. So before unfolding, a careful person could wipe the second inch and inside the top area of the bag, then unfold and handle the top inch in a manner that keeps it on the up side of gravity's influence so it remains clean. Nothing within an inch or two of it, should have time to seal before something runs up.
That said, I've also seen the vacuum pulling quickly draw rivulets of fluid toward it which might be the real concern here. But if one is not careless enough to allow that or situations leading to that, the double folding in "fold over, then fold that up under" would in any reasonable circumstance keep the leading edge, where the seal is planned, clean.