I used to work in a shoe recycling shop. It was sole destroying.
Why this joke works
A Job That Wears You Down
“Soul-destroying” usually describes work that drains a person's energy or enthusiasm. Moving the joke into a shoe-recycling shop lets “sole” replace “soul,” turning the complaint into a literal reference to the bottom of a shoe. The past-tense opening makes the speaker sound relieved to have escaped the job. Keep that dry, weary tone through the setup, then give “sole” a clean pronunciation without overexplaining it. The familiar phrase lets listeners catch the footwear switch immediately.
A closer look
Recycling makes “destroying” unexpectedly complicated
A recycling shop should recover useful material rather than merely destroy it. That makes the complaint sound emotional at first, even though worn shoes may be dismantled, sorted, or processed. “Used to work” also suggests the teller left because the job was unbearable. The line gets its best contrast from pairing an environmentally constructive purpose with a gloomy phrase, then revealing that only one letter separates the worker's soul from each shoe's sole.
Fact behind the joke
Footwear is part of the textile waste stream
EPA includes footwear within its clothing-and-textile waste estimates. For 2018, the agency estimated that the United States generated 17 million tons of textiles and recycled about 14.7 percent; the estimated recycling rate specifically for clothing and footwear was 13 percent. Shoes combine fabrics, rubber, foam, leather, adhesives, and other materials, so a “shoe recycling shop” points toward a real waste challenge behind the sole-and-soul pun.