Actually, not alleged, but completely false. It was a joke by humor columnist Greg Bulmash, who is also a blogger at http://www.brainhandles.com/
It is pretty funny nonetheless, so here it is.
According to www.bulmash.com: "No, he never worked for McDonalds, though he did work for Jack in the Box for 2 days in the mid-80s (mostly frying tacos before he got disgusted and moved on to bigger and better things). The job application was a joke (see the April 10, 1997 humor column below) that became an urban legend."