Miss Manners & Emily Post Never Had This Problem, I Bet

Doing my small part to combat ecological dangers (using tote bags instead of those awful plastic ones to transport my shopping) has posed a problem of shopping etiquette for me. Would it be terribly gauche to use a Wal-mart totes in the Bi-Lo supermarket if I forget to throw the Bi-Lo ones in the car? Of course, I would never think of using Bi-Lo totes in Wal-mart because their cashiers get a little testy using the ones with the Wal-mart logo on them. I wouldn’t want to incur their wrath by using a competitors’ bag.