First time here and I have a potentially stupid Q. From my childhood I have a lingering image of a LITB episode where the boys made homemade toothpaste and sold it at a fraction of store bought stuff. They got into trouble for it and I seem to remember them being taught a lesson in consumer capitalism. Does such an episode exist? Or are the brain cells scrambled. Thanks!

There is no such episode on LITB about homemade toothpaste. You must be getting another show mixed up. However, in the earlier seasons, Beaver did sell water to friends when the neighborhood's water was shut off for repairs. He wanted to earn money to buy a baseball uniform like Wally and the other boys. Ward tried to tell him that he was exploiting the situation and in the end he turned the money he earned from selling water to the boys.

Beaver and Wally also went door to door to sell a perfume called Flower of the Orient which smelled like an old baseball mitt.

In Andy Griffith Opie and his friends sold some worthless salve but never made it themselves.

The Walton kids sold a product called Pinky's bubble beautifier.
But I don't remember an episode of toothpaste being sold.