I did this when ttc for our first. I don't think I did it right, and I certainly wouldn't go by that alone, but you do get to learn what your body is doing and you do notice a difference from one day to the next.
The one thing I would say is that you have to be careful for the second half of your cycle in case you do get that BFP. You can introduce infections and you generally shouldn't really mess with down there atall.