In Chinese, the emotional coloring of a word can be either commendatory or derogatory decided by the context. Normally, you can use the same word in quite different circumstances. So you can use "狡诈", a common derogatory word, or "聪明", a commendatory word, to describe "a sneaky way". For your consideration, I think "狡诈"is not only correct and precise, but also make the sentence more colorful and vivid.
中文单词的感情色彩可以依据你表达的不同而不同。因此,你会经常看到同样的词被用在截然不同的句子中。在你的问题中,你可以将a sneaky way翻译为用褒义词表述的"聪明的方法",也可以翻译为贬义词表述的"狡诈的方法"。我认为"狡诈的方法"能够很好地表达你的意思,也使得句子更加生动活泼、丰富多彩。