Thank you all so much for the ideas, finally got it off with tarmenator. Boy that was scary, blue all over my blocks. DH thought that the coating must be coming off the iron, has this happened to anyone?

I saw a turorial on Sharon Shamburg's web site , she used a Mr. clean sponge. it can be used with a hot or cold iron. I haven't tried it yet. the sponge is available in generic....but it has to be wet to work.

I wad up a used dryer sheet and rub it all over a warm iron. You can work it into the holes, too.