Grandpa mentions Yancey's stump liquor; stump liquor, or stump hole whiskey, was illegally made whiskey that was hidden in holes of tree stumps in order to hide the stills.
The poem John-Boy is reciting to himself as he's getting dressed, just before Mary Ellen bursts in, is "The Eve of St. Agnes" by John Keats.
The ingredients for Yancey's Red Devil Chili are as follows: cayenne pepper, chili powder, paprika, peppercorns, Tabasco sauce, green chilies, hot chilies, green tomatoes, horseradish, cider vinegar, pork belly, beef cuts, bell peppers, chicken livers and squirrel shanks.
The radio contest Grandma enters is sponsored by Blue Ridge Bluing. Bluing is a household product used to improve the appearance of textiles, especially white fabrics. Used during laundering, it adds a trace of blue dye to the fabric. In many places, it has been replaced by bleach for its primary purpose.
The songbook on the piano is "Everybody's Favorite Songs," published by the Amsco Music Publishing Company in 1933.