Cleaning Bathroom Grout?

I recently moved into a house that is 70 years old. The grout is so bad it's black. The tile is pink (if that tells you anything). I have tried bleach, Oxiclean, Awesome, degreaser, you name it, I have used it. Nothing works. I can't afford to spend a lot of money on it, but am willing to try anything. The tile is on the bathroom floor, half way up the walls, and in the shower. Also, I have those sliding glass doors that I can't get clean either. Any suggestions? Thanks.