There are many brands of Dry Molly Film Lubes on the market that are every bit as good as Perma Silk.
I use Chemsearch's AEROLEX PLUS. It's the same color as the original mag color and is rated to withstand extreme temperatures and pressure.The nice thing is I bought a 11oz (normal size) spray can for $7.80. CRC makes a good Dry Molly product for $5.81. Check out some of the indistral catalogs such as Grainger and you will see what I mean.
I'm not saying there is anything wrong with Perma Silk other than it costs to much compaired to the other equal products that do exactly the same thing.