That picture of Boynton is either seriously out of date or he has access to something extremely potent. I doubt the DCVax + sweat sock theory and would go with the blood of virgins (favored by old oligarchs like the Queen of England and David Rockefeller ;-). Research on virgins is frown upon these days but progress has been made in the lab with mice: https://www.sciencemag.org/news/2014/05/young-blood-renews-old-mice
Or he could just be going to Panama City for stem cell treatments — lacks the cachet of virgin blood but at least stem cell therapies are legal there.