I second that, though I can look over to my wine rack and see at least two screw tops that were successfully corked. I was never known for being the safe one, you should go to your local wine store/bar and see if they'll give you a deal on empty bottles from tastings. My local does 10 or 5 cent bottles, depending.
However, if you insist on corking screw tops, make sure they're at least screw-top wine bottles, as they (usually) have straight necks, ensuring you relatively smooth corking.
Better to scrounge some proper bottles and be safe though.