hope everyone is well

my question: I have a brand new water heater that happens to be about 2 1/2 years old. i used it for three months and then it sat turned off for about 9. i would like to give it a good cleaning before i fire it up again. my concern is the stagnant water. although the system was sealed off, i'm certain it must have some kind of contaminants by now. i thought of flushing it out, but the water exchanging in the tank wouldn't be very effective. and in order for that to even slightly work, i have to waste a lot of water. if there was perhaps a more efficient solution. i imagine i could easily empty the tank with my air compressor (the water which i would use on the lawn), but then what? or am i over concerned about the whole thing.

tank: natural gas, 50 gallon, GE

i hope i posted this in the best possible board??

thanks