After installing a new coil, boil the used one in plain tap water for about 20-30 minutes and air dry. It will extend the life for at least one, sometimes two cycles. Save time and boil a few at a time. I did this when I used the Smok factory coils.
1. If you and your wife are vaping DL at 40+ Watts, you are going through a lot of juice. A few days at a few tankfuls per day is really not too terribly bad with those coils.
You might try the RBA kit that may have come with your tank. If it didn't come included, they're about $10-ish. You don't change coils with that--just the cotton. I use the RBA's with my Baby Beasts and the performance is great.
2. If "yes" to #1 above, the Estoc may disappoint. That's not a high wattage, high temp, high performance tank. It's a flavor chaser that's best just at or below 40 Watts. I like mine--coils last long and taste great. But cloud chucking they ain't.
