when you drown your plant all you need to do is keep the container she is growing in fully 100% Submerged in Water. After you have it fully submerged, keep running the lights 12/12 just as you are now and it could take 3-10 days for your plant to die off. Then you chop her down after she is dead. Trim your buds and hang them in a nice dry day place with some air getting to them and after a few days, 3-5 if your bud is dry then cut off the buds from the branches and put inside a mason jar and keep the lid on one day and the next day keep the lid off and keep going for a couple of days or just enough to make sure there is no more moisture in your buds and then you can seal the lid closed always. If you over dry your bud just put a fresh clipped leaf in your jar and it will moisten your buds again. If its too moist then keep the lid off or put in a brown paper bag. Ultimately no mold!!!!!!
Here are pics of my 2 last plants drowning. The Bubba Kush took 5 days and the Chocolope took 7 days.
Peace
BKB