Earlier quoted context omitted.
Jokes of this kind are funny because they reference an unstated truth that performer & audience know. They are one of the vehicles by which culture is created. If you think that a joke is communicating a mistruth (by which I mean something disputed, I do not mean a lie) or creating a negative culture - regardless of the intent of the author - it's okay to discuss that. So in this case, I don't think there's any reaso…
In your example you are replacing the labmates dangerous solution with a much safer one. How would you replace their "dangerous" phrasing with "safer" phrasing while still retaining the slight?
I tried reframing your question to, "how would you have made this joke, preserving the slight", but the joke isn't to my taste personally, which is only a problem if you ask me to rewrite it - I'm not expressing this as a criticism of the joke, I'm just the wrong person to ask, because when I try to imagine how I would've made the joke, the answer is I wouldn't because it isn't my sense of humor.
I don't really have a problem with the way events unfolded with joke being made & getting a footnote. That honestly seems fine to me, I don't think it requires tinkering.