I concur with Peter. IMHO, it is less about the shoe engineering than it is about the individual's feet.
In five Caminos, I have never had a blister. Yet, my feet are very problematic.
First, they are asymmetric. They are literally shaped differently. So each foot must have it's own care regimen.
Second, I have a persistent callous problem, worse on the right heel, that will see infected blood-filled callus pockets if I do not care for them every night. On my first Camino, in 2013, I required in-office surgery by a podiatrist at Burgos to treat them. So, as a result, I am very keen on the idea of caring for my feet.
This year, to combat the callouses, while passing through Porto, I even picked up a battery-operated "grinder" to remove the accumulated dead callous tissue on my feet. It weighs more than I would like, but it works wonders and is better than using a "cheese grater" rasp. The latter tended to rip off the good skin with the old, dead skin...yuk!
The issue of shoe / boot engineering is significant. For some people's feet, it can factor into retaining too much moisture in the shoe.
I am on my second pair of Keen Targhee II mid-height boots with Gore Tex lining. They are rated as waterproof and I DO stand in puddles to rinse off mud, so they must repel water penetration.
But moisture, and the friction it can cause, most often comes from sweaty feet. I have had days when I can almost wring perspiration from my socks. Yet, I get no blisters.
The point here is that everyone's feet are different. Even one person can have two "different" feet, as I do. Yes, they are the feet I was born with, and neither has suffered traumatic injury so as to reshape it, but each appears to have a mind of its own. Who ever said I was normal anyway?
The key here is HOW you manage your particular feet. What works for me is:
1. Boots that are a minimum of one to one and a half sizes larger than the Bannock device in the shop tells me that my bare feet are. This also requires checking with the footwear manufacturer to determine whether the particular style / model of boot or shoe runs larger or smaller than listed.
2. When evaluating boots to consider investing in:
A. I wear the EXACT socks I plan to wear on Camino.
B. I wear some backpack loaded with approximately 9-10 kg of something from the store, or I bring my pre-loaded Camino-ready rucksack to the shop if practical.
C. I shop at the end of the day, on a day when I have been on my feet a lot, to simulate waling-induced swelling.
This results in well fitted boots.
The next step is to determining how best to lace these boots to support my feet, and to avoid sliding that could cause blisters. Check You Tube for abundant videos on "How to lace hiking boots."
After that, I focus on socks. Over five Caminos I determined that what worked best for my odd, sweaty feet was two pair of socks.
The inner pair, closest to my feet is always a a thin, crew, microfiber sock. I choose black or navy because they do get grungy after a few weeks on Camino. This sock wicks moisture from the skin on my feet, keeping the foot relatively drier than it would be with only one pair of socks.
The outer pair of socks is always a merino wool blend Smartwool hiking sock. I have tried both medium and lightweight versions. This past April - May walking the Camino Portuguese from Lisbon, the Smartwool lightweight hiking socks worked great for me.
I am sold on this two-sock combination. It works for ME. Your results may vary.
Lastly, my nightly regimen consists of applying Vaseline / Vasenol petroleum jelly to my feet then a cotton sleep sock before I go to sleep to moisturize my feet while I sleep. In the morning, while booting up to walk, I apply more Vaseline / Vasenol to both feet before putting the liner socks on. I believe, and again, your results will vary, that this helps keep my feet moist enough to retard calluses, yet avoid blisters.
Finally, I learned of a book that I plan to buy. It was reviewed in the recent edition of La Concha, published by the American Pilgrims on Camino (APOC) of which I am a proud member. It is called: “Fixing Your Feet: Injury Prevention and Treatments for Athletes” – 6th Edition, by John Vonhof. The word Camino does not appear in the book, but it is a veritable bible of foot care.
I hope this helps.
