May go without saying but this is a valuable skill to try before you actually need to access the water. I drain my water heater once a year at day light's savings for maintenance on the heater. I use the water hose that's connected outside the back door, and drain the heater into the yard.

The gas furnace guys who come in February for annual maintenance on that thing offered to flush my water heater sitting next to it, no charge. I told them I'd done it in November and showed them the mark on the side of the heater. But a nice customer friendly service. Always remember to power down (turn off heater) and stop the incoming flow before draining.

Also FWIW - keep an old supply hose or keep your next supply hose handy in the event the connected supply hose springs a leak. I buy them in advance of what I need (one new pair in stock ready to go), and rotate them out after 5 years. Mark the new pair with the date you want to install them. I've heard that the braided steel type can last much longer but they only come with a 5 year warranty, ymmv. I gave my last pair - which looked terrific - to my Mom+sister to keep as spares.