Flatboack said: "He suggested it allows you to concentrate on specific aspects of your technique (like relaxation or shifting or touch etc) and build them with your full concentration."
EXACTLY RIGHT. You must isolate discrete aspects of technique and concentrate only on one thing at a time. Rabbath talks about this in his video.
I had hack violin teachers for years who did not teach this practice method of isolating techinique. Then the Music God deigned to bring me a great teacher. Jerri had been a student of Ivan Galamian himself! Jerri told me to put away all the music books, stop playing etudes, and to do simple, easy, repetitive exercises. These exercises seemed totally unrelated to music: "relax your wrist -- let it hang from your elbow". "think of your shoulder as moving in a circle as you up bow and then down bow". "Play finger patterns like 1-2-3-4, then 1-3-2-4, etc." (All this was on the violin). After a few months of this stuff, my playing significantly improved. So much easier and my tone was vastly improved.
A few months ago I decided at long last to play bass (YIP YIP HOORAY!!). I promptly rememebered Jerri's advise ala' Galamian. I started slowly with basic elements of technique. Only do one simple little thing at a time to the exclusion of all else. Go snail-slow at first and get the feel of it and do it perfectly. Watch yourself doing 'it' (whatever 'it' is at the moment -- for instance the shape of the left hand and the contact point of your fingers on the a particular pitch). The Zimmerman book "Contemporary Bowing Technique for Bass" is totally this method relating to bowing patterns. I cannot recommend this procedure any more highly that Ivan Galamian and Francois Rabbath.
This method works faster than any other to achieve a technically proficient playing style. Without good technique, you can only hope and pray to ever sound good.
Roonz