No offense WDK, of course the circuit breaker should not be used like a light switch when entering and leaving a room on a daily basis but the occasional turning it on/off when not in use will not harm the breaker, that's what its for.
If one has the skills or money then certainly wire the switch in a convenient spot and use it.
In addition Fr27davis if your concerned about breaking your, I'm assuming plastic hot water heater access spring "latch", you could replace it with a metal one. They're pretty cheap.
But again, if you have the time, skills or money, go for the additional switch.
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