I'll try and work on it this weekend... but if you want to get started sooner, the objective isn't slow-attack, but rather no-attack. The first or second effect in his chain is compression. Then it goes to whatever you chose, Boss SG-1, EHX HOG, EHX POG2, EHX Attack Decay, volume block (w/ADSR modifier), and you shave off only the pick attack, nothing else. That then goes into another compressor whose purpose is to slam the guitar's sound back to the beginning of where you picked the note so it doesn't sound like you're always behind the beat. Refer to post #18 in this thread to get a sense of all this.
Kurt's intention is to remove the percussive sound of the pick attack so that it doesn't interfere (at least in the jazz context) with the drummer.