Capt. Obvious here...
If a lady does her research and decides the guy won't be a good client for her, her response kind of depends on the real reason. If the reason is because he's psycho, professionalism be damned, don't bother responding.
If it's a perceived personality problem, if the guy wants a quickie and that's in your wheel house, he may question why personality matters in that case, and be put off. In that case also, why bother responding?
If you read his posts and get mixed feedback from girls, and you're not sure, there is always the ignore feature.
If it is truly a mechanical compatibility concern, for example, you speak Greek but selectively, and he wants to speak Greek with you, then you might have a chat. If he's okay without foreign language if say you speak different dialects, lol, then...