On some cAAriers, there is absolutely a procedure in place. If the offensive odor is detected on the ground, the LCRO is called to determine if there is a medical reason for the smell. If there is not, the pax is discretely asked to freshen up within their powers, or the airline will help them if they are unable.

If it is deemed a medical condition, then there is truly nothing to do but accept the pax, and try to reseat those that are unable to understand and accept the situation.