ohh, ok i gt it now.
Nope, sorry mate, i don't know of a mel script that will do that.
Though i'd think it wouldn't be hard to write a mel script that will create a shader that has the wire frame to true and transparency set all the way up, and toggle that shader and the default shader back and forth.
May-haps one of the scripters on the forum can write one up real fast? I don't script myself, or i'd give it a go.