If you pitted all of the fast food mascots against each other in melee combat, you'd end up with Harlan Sanders atop a mountain of skulls, sitting in a throne of blood.
This is awesome. You probably have enough stuff already, but there's a whole bunch of books from the 19th and early 20th century on Archive.org that might be useful for your lessons.
I went on a downloading spree a few years ago when I thought they were going to take the Internet away from us and I have about 250gb of ebooks saved. I know a lot of people turn their noses up at ebooks, but nigga its free knowledge.
The International Library of Technology is a good place to look for old knowledge in lesson-sized bits. It covers everything from steam power to electricity to hand lettering doors with gold paint.
I went out and met the Goat Farm people at their farm one time. They moved to Alabama and started a farm specifically as a home school project. The kids take care of the goats, do the milking, make the soap, do the graphic design for the packaging, and they seemed to enjoy all of it. It's like the most happy form of slavery I've ever seen.
Chinese make century eggs, which are preserved in a caustic basic substance and taste like they came from Satan's asshole after he ate too much taco bell.
The burying in ashes thing is probably a reference to the method of preserving tomatoes by storing them in layered wood ash.
I had a friend who married a girl from up north, and when he went to Thanksgiving dinner with her family, his mother-in-law offered him "Pee Can Pie." He said he would love a slice of pecan pie. They made fun of his pronunciation, and he looked the mother-in-law in the face and said, "Do you grow them here? No? It's 'puh-CAHN.'"
Then he explained that a pee can is what you keep under your bed so you don't have to go to the outhouse in the middle of the night.
Professionals will listen to recordings of their own voice to remove regional accents.
I got rid of my Southern accent when I was working in film and TV, because there is a lot of anti-Southern prejudice in that industry. I put it back somewhat when I got out and went home, and realized that Alabama really is superior to all other regions of the US.
When my dad would work with yankees, he turned the drawl up to 11. They assumed he was literally retarded and would say things in front of him that they never should have. He always thought that was funny.
Southern Whites have IQs above average. Southern negroes bring the average down. It's the same with quality of schooling. Most yankees are not smart enough to understand that and assume that a low average IQ/low average school score in the South equates to everyone being stupid and uneducated, and not just that there are segregated nigger schools full of 75 IQ monkeys that massively skew the average.