This is one of my favorite easy cleaning tips. It requires little active time, is super easy, and inexpensive.
1. Plug the tub drain so that the water can fill up.
2. Pour about two cups of bleach into the tub.
3. Fill the rest of the tub with water.
4. Let the bleach and water soak the tub for a couple of hours. I usually do about two hours.
5. Drain the tub.
6. Rinse well with water.
7. Any soap scum, grime, or dirt should wipe away easily with a towel.
8. Rinse well again.
I use my shower head to rinse the tub.