It's not so implausible:
The question isn't whether it's plausible or not-- this is Indiana Jones, after all. The question is whether it worked in the movie. The whole scene is bizarrely out of place and is making light of something that most people don't think is really all that funny.
In a similar vein, there's nothing wrong with funny characters necessarily, but there is something wrong with Jar Jar.
That's funny; another of Mr. Lucas' fine films taught me that you can survive a direct nuclear explosion by hiding in a discarded refrigerator.