Only after I finished the job, I realized that I could have done one better: To get even the very last bit of oil and dirt out of the rear axle (despite Jaguar fairlure to provide a release plug), I could have done, what I have drawn above: attach my metal pipe (which you have seen in the pictures) to a hose, and that to a solid and airtight jar as in the sketch and connect the second pipe to an old vacuum cleaner... I;ll do that next time.