While it would be nice to see some page examples, you guys are judging in absence of any evidence. First, JOOLS, he's talking about how and what to practice when you DON'T have your bass. At first I was thinking "Jeez, you don't need a book to tell what to practice when you can't put your hand on your bass" but, based on the above responses, I guess that's not true. But look at his 'table of contents':
VISUALIZATION - you're sitting on the train or bus, you've got the melody to Ron McLure's APRIL IN NIMES in front of you. As you read the pitches, visualize the fingering, the position shifts, where and with what finger you're going to make the attack to the string, where you'll slur etc etc. The more detailed you can do this, mentally, the easier it is when you actually have the instrument in your hands.
EAR TRAINING - sight singing new lines, singing intervals, identifying root movement of the music playing in the elevator, singing chords - you can do all of this pretty much anytime you don't have to consciously pay attention to something else (like your job), but driving you can do everything except sight singing. If you have some kind of player, you can make a CD or upload soundfiles that have chords or progressions or intervals or WHATEVER ear training you're currently working on and practice that while driving, jogging, washing the dishes whatever.
And so on and so forth. I'm not sure I'd classify that as a "load of worthless tripe"....