I almost didn't think this deserved to be an answer, but here goes:
Have you ever attempted to ask the offending person? (I didn't mean for that to read as being confrontational, on my part.)
Even if you have done so in the past, and needed to resort to other means when the accused party failed to respond, or even acknowledge your question, each person is probably not the same as those others.
Your first recourse should always be to ask the other person if they are aware that their bodily aroma could be causing offense to others.
It would work best if you didn't presume to condescend upon them as if they were a child being scolded, either: most people — those not simply indolent or inconsiderate — would take that as a sign that you are not worth a rational discussion.
Maybe they aren't aware; maybe they are aware, and have a perfectly reasonable explanation — delayed flight, inconvenient layover, temporary financial hardships, dire circumstances, refugee, so on. You might think it frustrating to listen to their arguments, yes, but this strategy applies to broader situations too: e.g. if the offending odor is not bodily funk, or even an odor at all.
The other person might be uncooperative; the manner by which they do so may be informative as to what other recourses are available to you.
Keep in mind that you can expect any perceived differences of social strata between the two of you will change your optimal approach.
Yes, in a moment of indignation, most of us tend to assume offense and to blame the other party, but unless the situation calls for such hasty responses, it is better to take a moment to fully assess all the possibilities.
Okay, I'll end so that it doesn't sound like I'm being preachy.
Anyways, this is really less of a topical answer, and more to broader interpersonal encounters anywhere, I suppose.
The gist of it is that discussing with the person might not help immediately remedy the situation between you and the other person.
Hopefully, it at least helps to ensure the second person will be easier to work with; rather than scrambling around them, confront them directly first.
It also tends to make for a better society: If the first party behaves like an adult, and treats the second party like an adult, then not only are they given more incentive to behave like one, but the first party is less likely to appear juvenile.