I swear by using vinegar and bi carb soda. Everyone talks about it, so I thought I would use it. After someone has had a shower and the glass is wet and 'hot' wipe bi carb all over it, I use one of those green scourer sponges and spray vinegar on it, then scrub it (easy scrub, little effort needed) leave it to sit for 5mins, then rinse off with hot water. Our glass looks brand new, so easy, no stinky fumes, and so cheap!