You can go out and forage for wild mushrooms without digging through cow dung. "Mushrooms grow on cow dung" is true, but not the whole truth. It's part propagan

You can go out and forage for wild mushrooms without digging through cow dung. "Mushrooms grow on cow dung" is true, but not the whole truth. It's part propaganda to discourage people from eating them. Mushrooms simply grow anywhere that is very moist and nutrient rich. Cow manure happens to fit the bill quite well - and there's a high probability that spores will find their way to the dung, because the cow grazes large areas of a field, and the spores it eats survive digestion. However, you can find mushrooms simply by inspecting the fields yourself. They're typically found in the bottom of a valleys where moisture is high, on fields where animals have grazed. Also in the woods, under pine trees, and they grow on plant beds covered in wood chip (non-bark). Also, even where they do grow on dung, the part of the mushroom you eat (the fruiting body) grows above the dung. The mycelium grows inside the dung, which you don't eat. You break off the fruit at the stem, without touching the dungs. You can wash the fruits before eating or drying them.