I don't have the Nautilus (yet), but I do have both the Aspire et-s and Vivi Nova (which, I believe, have similar coils). And because I'm still trying to find a couple of ADVs, I switch out juices a lot.
I vape 100% VG and I noticed that even after an Everclear soak and a 15 minute medium boil, I still had residue on the tanks (not to mention the coils).
I now add about 1 teaspoon of vinegar to 2-3 cups of water when I do the boil (that's an estimate on the liquids, I don't measure). After the boil, I hold the coils vertical under running water (to rinse off the vinegar).
And I let them dry for at least 48 hours. Maybe it's the Florida humidity, but 24 hours is never enough dry time for me. After letting them dry, I do a dry fire -- if I smell vinegar, I do a pulsing dry burn until the vinegar smell is gone (which I haven't had to do since I started rinsing them under running water).
This has worked really well for me -- but you don't want to overdo the vinegar. Vaping vinegar really clears the sinuses and curls the nose hairs. <knowing nod>