Worthwhile if you don't use it for a year but not worthwhile if you go there every month. Turn off the water heater heat and drain the tank and leave the drain valve and also several hot faucets open.
(Be sure to refill the tank to the point of having a hot water faucet open and running smoothly before turning the water heater heat back on.)
When cleaning anything including baby diapers, it is better to sweep off or scrape off as much solid and semisolid material as you can first. (1) Less cleaning fluid or detergent needs to be used, (2) Less of a mushy mess which in turn means that bleaches or disinfectants will be more effective.
Not going to do it any harm but if it's going to be that long I'd concider not only shuting it off but draining it.
My concern is bacterier building up inside the tank sitting that long.
Just make sure to leave a note for yourself so you do not turn it on without refilling with water.