Thanks for resurrecting this old thread... it an interesting issue.

One solution to Artkansas's dilemma would be to organize a group of 20-30 cycling grocery shoppers, pre-announce their arrival so the store manager is present and proceed to do their grocery shopping with panniers/backpacks. I think the manager would be leery of mistreating 20-30 paying customers, particularly in the grocery business.

There are a lot of situations facing cyclists that are insurmountable when we deal with them alone. But get enough people together and solutions can happen.