I have a pair of Miura VS but they have tight spots I'd like to stretch. While at a shoe demo at Smith Rock, an employee from the local gear shop stretched shoes with a broom stick and a microwave. I wasn't able to catch the settings and I wasn't sure if this would be a great approach. I know that ugly toes are the honor badge of a hardened rock monkey, but I'd like to avoid pain. Will the Gear Guy speak?
You are a smart rock monkey to avoid the foot pain caused by rock shoes, which can inflict a smorgasbord of maladies including hammertoes, bunions and Hallux Rigidus, the unfortunate, irreversible and irreparable condition where your big-toe knuckle, over an agonizing period of, say, 20 years, grinds its cartilage into crushed glass before fusing completely rigid. And all this can be caused by proper-fitting shoes. Imagine what a misfit pair can do.
I've heard about drying a poodle in a microwave, but have never considered using a microwave and broom handle to stretch rock shoes. I haven't used the microwave technique demonstrated by your gear guy (I hate him), but know he's an idiot. If your shoes have any metal, such as metal eyelets or buckles, zapping them in a microwave will spark an electrical storm that will end the world. And even if your shoes don't have metal, just a few seconds in a microwave will turn the rubber into molten goo. Does that sound good?
Another problem: not much of a rock shoe can actually be stretched. The rubber rand, toe cap and heel rand will temporarily stretch, but, like rubber bands, will soon spring back. Really, you can only stretch the upper, and only if it is leather since most synthetic uppers are made not to stretch. Your Miuras are leather, but have an anti-stretch, synthetic lining. Tough! I do, of course, have a simple tip, one that has served me well for eliminating shoe hot spots, at least temporarily.
Put on your rock shoes and take a hot shower. This will feel queer, but don't give up unless someone is watching. Next, wear the shoes around the house until they feel like they have stretched. Again, do this when no one can see you. Stuff the shoes with newspaper to dry, and go climbing in them while they are still damp. Afterwards, re-stuff with paper.
I have had shoes immediately stretch a full size this way, but I also came out with bright blue, purple or red feet as the shoe dye usually bleeds.
You can avoid all of the above simply by getting shoes that fit in the first place. When I began climbing, in the Bronze Age, we stupidly thought that you had to crush your feet to achieve maximum precision. Fact is, shoes only need to be snug -- I'll buy you a Brannock device if you ever fall because your shoes were too comfortable. Gear Guy has spoken!