That's fine. I use just 1 drop of dawn in a wash
No matter what atomizer your using they all manage to get juice film on them. Just hot water doesn't clean them, just rinses them off and the film is still there. I use just a bit of dish soap when I clean and a mini brush from fasttech that also fits nicely into driptips. Never have tasted soap yet in any atty.
I'm not sure about using vinegar to clean attys but I do put some vinegar into the pail of Murphys oil soap that I clean our laminate floor with, it knocks the suds down so your not moping suds all over the place. It should work in a ultrasonic the same way but still vinegar is IMO iffy.