Caches get placed inside and outside businesses at times. The key is to talk to your reviewer. Explain your intent and the situation with the business. The reviewer may even want to contact said business. Most reviewers will work with you to make sure what you intend to do will fall within the guidelines. Personally I don't like going into anything other than a library to find a geocache. Have had some negative experiences before, but also some good ones.
Talk to your reviewer, and good luck.