My Milano backstrap sandals are very comfortable. Once you slip into them, you'll wonder why you missed them. Naot makes similar sandals, some with removable cork and latex insoles like my Lappland. Ohhh... sheer bliss. For people who prefer style over function, comfort footwear gets ridiculed. But when you have to stand on your feet or walk all day, they make a difference.
You can get the cork outer edge sealed over with a leather trim. This will eliminate cork maintainance and drying out and keep them lasting longer. Then all you have to do is replace the liner and heel sections as they wear down.