Including the setup for the gate, a slalom pass takes about 20 seconds. Do the math and it becomes depressingly obvious that a fit keener is lucky to get 10 to 15 minutes of actual course skiing practice per week. That's about 8 to 12 hours per year ... if you live in Florida. A serious golfer spends this much time practicing DAILY! Making progress with 15 minutes of practice per week is guaranteed to test the patience of any card-carrying Type "A" baller.
What do you do to accelerate your slalom progress, other than skiing itself?
... Your ski should be your dance partner, not a wrestling opponent