The appearance of your candidate can be just as important as their skill set. If your candidate is meant to be placed in a client-facing role or in a sales position for instance, it is especially important that they are presentable and professional. As an Agency Recruiter, you know that you would not send your client a restaurant management candidate who had poor hygiene or a legal assistant who wore sweat pants to an interview.
The interviewer wants to see that, no matter how talented your candidate is, you would be comfortable handling the situation appropriately. Yes, it's uncomfortable to tell a candidate that they need to clean up their appearance; however, you will come across uncomfortable situations like this as an Agency Recruiter. Discuss how you would handle the dilemma. If you have ever experienced this situation, you can give a real-life example by telling your story using the STAR framework (Situation, Task, Action, Result).