Plated bullets are fine for use in a glock. I have found they can in fact be loaded to jacketed data, in my glock at least, without losing any of the plating or fouling the barrel.
That aside, shooting lead can be done in a glock barrel. Should you try it? That depends. If you are going to do it you need to know how to identify barrel leading and overpressure signs. I shot lead for a long time out of my stock g21 barrel before I replaced it with a Lone Wolf. I have found that the .45 tends to have a lot less problems with leading than the .40s.