Porisoty in a rim.

I've got a rim with porosity I was reading in Popular Mechanics about a GM repair using sicilon for this. Any idea about how much this costs I can buy a radial tube for appx. $20.00 delivered and install it myself. I have a bead breaker and can get one side off easily but the other side is a lot harder and don't feel it is worth the effort.
Anyone have experience with this repair.