A big thumbs up regarding the technique of steeping e-juice in an ultrasonic cleaner. Real simple: One 120ml bottle of Strawberry cream that was weak in flavor, fresh made. Placed bottle open in cleaner with the water almost coming up to the level of the liquid in the bottle. Turned heater on to 50deg C. Turned on cleaner for 30 minutes. Very noticeable increase in flavor. I am going to add this technique as a finishing process for all my batches. Followed only by applying the label.
On to buying more flavorings!!!!