Replacing Invisalign Refinement Aligners Every 7 Days?

I've just started my Invisalign refinement and am on aligner 1 of 10. My ortho's assistant has instructed me to wear each aligner for 7 days. She assured me that if my aligners are seated properly, I can change them weekly. She suggested using Chewies several times a day, in order to get them seated. I asked her why my case was special enough to change them weekly and she said my teeth were "loose" and were able to move quickly. She assured me she did the same for her refinement, as well.