Parentheses to indicate the word can be singular or plural (APA style)
Stylistically, it is recommended to choose the most clear and unambiguous terminology, to minimize the risk of a reader misunderstanding. By this metric,


  the props


is a poor choice, because the reader might have forgotten that there might only be one prop, and your writing fails to correct their misunderstanding. I suggest


  the prop(s)


because it is common and standard terminology, unambiguous, and less clunky than "prop or props", which tends to interrupt the flow of the sentence.