I have an customer service representative employee who suffers from nasal allergies. He makes horrible noises, snuffling up mucous and clearing his throat with his mouth open. He doesn't bring his own tissues but uses up all the toilet paper in the restroom (then often leaves it floating in the toilet, which is also a customer space). I have asked him not to make the noises and to take a non-drowsy anti-histamine to deal with the problem. He has not done so. What can I say to him?
This is a hard situation. Here are the steps to take.
First, you did the right thing in speaking to the person. Sometimes this is all that it takes. Sometimes people do not know what they are doing and some insight rectifies the problem.
Second, if this does not work, a second reminder would be necessary. Try to do it in a tactful way, to make sure that the person is not needlessly offending. But this time, you should document this and perhaps even bring in another person as as witness.
If this does not work, then you may have to give a warning, because you might have to fire the person for not doing his or her job well, if there are customer complaints. This last point is the key. You need to make sure that this person know that his or her job performance is being affected by this habit.