Boiling glass is ok as long as you don't immediately put it under cold water and rinse it off. Cold or hot water actually does nothing to glass, merely expands when it is hot and shrinks it when its cold. It is when there is a sudden change of temperature that the glass cracks. As far as what cleaners I personally use, I use Simple Green. There are actually threads devoted for that stuff. Just search it up. With SG, all I have to do is soak it in there after I am done with it, and then rinse it out with hot water a couple of hours later and it is completely clean!