One preventative measure that I rarely see in these threads is take a hard look at the distance you walk each day. Dry feet, yes. Vaseline, yes. Large shoes, yes. Two layers of socks, yes. Taping your feet, yes. All of these show up in each of these threads. All work for some, and don't seem to work for others, as was pointed out in the OP.
Another to add to the mix is to walk a bit less each day. In my 2016 Camino, my son was getting terrible blisters. We took a rest day in Burgos and that seemed to have fixed things. But as we crossed the meseta we started to walk longer distances and they started to come back again. By the time we reached Astorga after several days of 25-30km distances (which is not excessive by many people's standards) they were really terrible again. We paused in Astorga and had them treated. After Astorga we were sure to walk less than 25km each day. And they didn't come back.
So if the other suggestions don't work, try just not walking as far each day.
Of course, it is handy to have some cushion built, not just into your shoes and socks, but into your schedule to allow you to make this adjustment.