How to improve iPhone 5s finger print recognition

I just herd how to do this from Security Now so full credit needs to go to Steve Gibson from GRC.com for finding this.
There seems to be a method of training your iPhone 5s touchID sensor after the initial setup of a finger.

1. Go into the Settings app and select General.

2. Select TouchID & Passcode.

3. Enter your current Passcode.

4. Select TouchID.

5. Now touch a finger (that you have already registered to your phone) to the sensor. You will see that when rhel finger is recognised the co responding finger number will be briefly high lighted.

There is no official documentation for this but it does seem that touching your finger to the sensor while on this screen improves the print data on the phone and makes scanning of your finger more accrete and as a result more likely to unlock on first scan.