I started climbing almost three years ago and my first pair of climbing shoes were 5.10 Rouges. They worked great till the soles wore out. I decided to upgrade to the 5.10 Dragons because unlike the rouge, the Dragon's sole goes all the way up to the tip of the heel making heel hooks no longer painful for me. I wear a size 11 5.10 rouge shoes so I decided to buy a size 11 for my dragons. I guess since the heel has a greater constraint on the shoe, my 5.10 Dragons don't really fit correctly and I can't wear them for more than about 5 minutes. I wore them once every few days for a whole month and still progress. I haven't tried to stretch them with anything aside from my foot. I wanted other peoples opinions if I should sell or keep stretching the shoes. My plan to stretch the shoes are to place water bottles and have them freeze overnight.
Stretchign them with anything other than your foot is not really an option because you'll kind of negate the point of having precise tight fitting performance shoes by stretching them in inappropriate places.
In reality only you can decide if the shoe is too small. Does the fit have a negative impact on your clmbing? Do you think your footwork is suffering as a result of pain and/or numbness. If the answer to any of this is Yes, the yes, get rid of them!
You can have them resoled and ask the resoling company to make them a 1/2 size larger. I did this with a pair of my old shoes. I asked them to make them a size larger and they did...worked out perfectly. When I inquired with the company they said they can usually size up toe 1.5 sizes bigger.