When I was pregnant I had to see an endo specializing in pregnant diabetics - anyways, the nurse there told me that you shouldn't use alcohol to clean the site before an injection because you are robbing your body of its own "good" bacteria, etc...so, I stopped using the wipes and I also stopped getting all the little bumps that I used to when using them.
I also always change the syringe but Lancets and pen needles are rarely changed
Always through the clothes --no wipes and use the syringe 'til you can't read the numbers. Some how the dull needle is worth it the end. One use and throw away, almost seems wrong.