Does this seem like a safe alternative to a boiling water bath?

Simple answer, no. Never tested and sure never approved.

The author says in the article that it is a deviation from the standard approved process so that answers your question right there. Who can know why she chooses to encourage people to use unapproved practices, but why would any one do it when she says it isn't the accepted norm?

Notice that the last instruction above is different from the usual boiling water bath instructions. For regular boiling water bath canning in an open pot you must cover the jars completely with 1 - 2 inches of water above the lids.

A PC can be used as a BWB canner, many do, but the jars still have to be covered with 1-2" of water or you can end up with air still in the jars and a weak seal.

Dave

Here is a link that might be useful: the article link

I wonder who tried to come up with that ? NO, not safe, just as Dave said and for the reasons he said.

The only canning procedure I know of that fills a water bath up to the neck of the jars is from Oregon State Extension. It's canned walnuts, so basically it uses a BWB to vacuum-seal the jars, nothing else.

Personally, I can't even see much advantage to the method other than saving a few cups of water. Why not just do a regular boiling water bath and avoid the worry?

Carol