With all due respect, putting petroleum jelly inside one's nose, let alone anywhere on the body, for allergies has got to be the worst advice I've read in a long time.
Petroleum jelly is made from petroleum products -- chemical compounds that were never meant for human consumption or application, and in fact are responsible for not only certain types of "allergies", but also serious problems like immune suppression, liver function problems, kidney problems, etc.
Vaseline Coated Inside the Nose
Using a petroleum product can cause problems down the road (or immediate). Try something that does the same thing that isn't petroleum based