This is a hint I read about that was very helpful for me. For at least 3 weeks play only the first 3 holes. If you are just messing around or playing along with a song on a CD, play only the first 3 holes. There are 12 notes in those 3 holes and you will forced to work those bends to make it come out right. It will also make you more versatile, having to use different technics to make the song work. I can now go right into a hole bent, come out of the bend, right back to another bent hole.
After 3 weeks add the 4 hole. Do this for 3 weeks By this time you will have the first 3 holes jammin' and with the 4 hole added.........Wow!!
You just got to stay with it and only it and you will be amazed at what it will do for you.