It has taken a long time to figure out how to keep the liners clean, colorless, and not stinky. In the morning, daily, I wipe them out gently with a a toothbrush to get the mouth slime out of the narrow spots. Then I soak them for 5 minutes (no longer) in an antibacterial mouthwash, then 5 minutes (no longer) in white vinegar. I keep the solutions in small jars and just replace them weekly. I don't have any food or drink contact the liners in my mouth, except water. I am fanatic about rinsing them immediately every time I take them out of my mouth, again to keep the mouth slime from hardening. Finally, 7 days after I start using a set, I use them to hold a peroxide tooth whitening solution. This ritual keeps them with no color and no smell.
Other advise--I put new liners on at bedtime and sleep through the discomfort of those first hours.
I am DELIGHTED with how much my teeth have changed over the last 10 months!