Trying different method of fresh water tank sanitization

I wonder if it would not be good to pull the rod, replace with a plug, unhook the cold input line, pour a gallon vinegar, fill with water, re-connect, and heat for hour or so. Then with heater off pull plug and flush heater.
As for the beach smell/taste; Fill, drain, then wait a day. Most smell will be gone when you refill.
I talked to a full-timer about his fresh tank. His rule was taste/smell water before put in tank. If pass that test fill and add a qt of vodka