seemingly useless or lowly items, like cow urine and horse-puffball fungus, that nevertheless have their own specific uses

即使是牛溲马勃，在良医手中也能发挥出意想不到的疗效。

idiom · insignificant or worthless things, especially referring to low-quality writing or trivial matters

这篇论文充斥着牛溲马勃，缺乏深刻的见解。