Even if it is temporary, so what? Can't you just repeat it? And wouldn't clearing these drainage channels be harmless (modulo risks of any surgery) even if the theory didn't pan out? If I had early-stage Alzheimer's I'd go to the ends of the Earth and do everything I could to slow it down.
> Can't you just repeat it?
I wouldn't assume you could. I guess that's why people study these things.
Repeat it? It's not removing a tumor. It's adding a path between lymph nodes and blood vessels. You can't just repeat that. After the surgery that path exists. It's a permanent functional change.