coolant flushing...?

Depends on how bad it is. If it's just a routine coolant change i just flush it out really well with a garden hose and refill with new antifreeze and distilled water

if it's worse than that you can get a bottle of quality radiator flush to run through before draining such as:
Amazon.com: Gunk C2124 Super Heavty Duty Radiator Flush - 22 oz.: Automotive

If your thermostat housing is leaking at all you may as well replace the gasket at that time as well as the thermostat

also just throwing this out there, I added this last time I did a flush, it's overkill as long as you keep fresh antifreeze in it mixed properly but my drain petcock was broken anyway so I replaced it with this:
Amazon.com: Flex-a-lite 32060 Zinc Anode Drain Plug Kit: Automotive