I would bet on the outside. Contamination comes from illegals locked in with the produce for days at a time. The ‘maters can be whistle clean as they pass border inspection only to be shat upon a few miles down the road.
"You've seen those half mile to a mile long rows they grow in California, haven't you?"
"Yeah, what about them?"
"Did you also notice the privies at the ends of the rows?"
"Yeah, what about them?"
"If you're in the middle of the row, and you have a sudden attack of gastro-enteritis, do you think you'd make it to the end of the row?"
He never ate uncooked or unpeeled vegetables, except ones grown by small, local farmers, after that.