How many leaves to dispose of? A whole deciduous tree or just the old garden prunings? If it’s not many, a zero effort alternative is just scatter the leaves around the garden beds. They will dry or rot depending on the weather, act as mulch for a while, and then breakdown into the soil. Natures compost, just like in real environments. If you have foodstuffs you want to dispose of, that’s different and composting is the way to go.