Frank brings a bottle of Pouilly-Fuissé to dinner. There would be no place in Mayberry for him to buy a French wine, or any wine for that matter.
When Andy is helping Aunt Bee with the dishes, Aunt Bee is washing and Andy is drying. But nobody is rinsing the dishes. Aunt Bee is scrubbing each dish briefly with a sponge on a stick and handing them one-by-one to Andy who just dries each one without rinsing -- very unsanitary.
If Frank, played by Charles Aidman, is supposed to be so smart and cosmopolitan, he should know how to pronounce the name of the wine he brings to dinner at Andy's house. Its correct pronunciation is Pouilly-Fuissé, with an acute accent on the final e. Frank neglects to pronounce the final e.