Christianity Today addresses this interesting question here. I think the answer would depend on a variety of considerations such as the reason for the dismissal, orthodoxy, and what the resource is being used for. If one is well-grounded biblically and theologically, and can think critically, then one can use such sources with discernment. However, if one is going to refer or cite such sources in a public setting (e.g., sermon, Sunday school class, article) then citation might convey the idea of approval. Here it might be wiser to use another source.