> hot water tanks should be purged yearly (to get rid of the debris collecting on the bottom)
Note that this is only the case if you have been doing this already from when it was new. It isn't necessarily a great idea to try to purge on an older water tank since the valve can start to leak if you open it and it hasn't been used in a long time.
There are still some Taco Bells that sell the Chili Cheese burrito (at least in the Mid-West US)! Unfortunately not as cheap as it used to be (its ~$3 here), but any time I go to a Taco Bell I always ask just in case.
Note that this is only the case if you have been doing this already from when it was new. It isn't necessarily a great idea to try to purge on an older water tank since the valve can start to leak if you open it and it hasn't been used in a long time.