Just a suggestion.
Use a garden sprayer, the ones that you pump up pressure, and pull a trigger on the wand.
Put your vinegar/water mix into it.
On the hot water tank, there is a drain plug for winterizing the RV, and emptying the hot water tank.
Insert the wand end through there, then twist and turn the wand to get full coverage in there, then let it drain out.
I think that is what I would do.
But for us, unless there is odor coming from the water, I wouldn't bother, but that's just me.
And if there was, the holding tank would smell rotten too, then I would watch where I filled the tank from.
Some well waters can have a strong sulpher smell, I know!
You might still see me rolling down the highway on my motorcycle, when not at camp.....