When refilling the same day or next day with same flavor I just fill and vape away.
If the juice looks a bit thick after several days in the tank when it's empty I rince with hot water (no flavor change) refill and go.
If I'm changing flavors, I throughly rince in hot water all parts, then soak in vodka for 15-30 minutes, toothpics, q-tips if needed, inspect, dry, quick 5-10 sec dry burn if needed, then fill n go.
Coil quicks working, or consistenly not getting good vape, replace with new one as needed.
May get into rebuildable tank but for now I'm happy with the Kanger Aero Tanks, Iclear 30S and Kanger Protank II's I'm running.