On the other hand, I replace them every two weeks (so any residual will be GONE at least once every two weeks), and I'll only use it for 9 months or so, though I'm thinking it might still be useful for cleaning my inevitable retainer for much longer than that.
So, my question to you is, is it worth the $100 + $10 every 3 weeks? (The price is almost negligable in comparison with what I'm paying for the treatment itself)
Is it worth it?
Maybe (see comments)