I was thinking of taking my car in to have the coolant system flushed professionally.
both not to have to deal with the old coolant disposal, and making sure all the flush gunk got taken out before putting in new coolant.
Since I found all the rust and stuff in my 65, this seemed like an easier way to go since the parts stores don't take used coolant.
So I watched a couple of videos on how they do it and wow, what a terrible tool set they have.

The first one was the worst and can't see how it would work on my car let alone many new cars.
It pulled and pushed from the overflow tank.
They had a big plug that filled the fill hole on the overflow tank and sucked coolant out, I am guessing vacuuming it out of as much of the rad as it would let it. They showed about 2 gallons pulled out. I can't see that getting more than half if even out of a system.
They they pumped it back in the same way. Over pressuring the over flow tank to force coolant back into the radiator cap.

The second video was better, but not by much.
The second one put two adapters in the top radiator hose and radiator to push fluid into the radiator as it pulled from the top hose.
I would guess 75 percent due to mixing, and heater core and bypass hose as the cold fluid shuts down the thermostat.

are there better machines out there? not even sure what I expected.

Like many easy tasks, if you want it done right, do it yourself.

Is a shop going to remove the block drains or just drain the radiator?

You can also go a step better with https://www.evapo-rust.com/restore-your-engines-cooling-system/

thanks didn't know they made that. picked up a couple qts today to give it a try.

Probably depends on the shop as well as the vehicle. In the old days we used to use the heater hoses to flush the entire system. Could flush it with a hose until it ran clear and then drain out a gallon from the radiator and fill it back with new antifreeze. I have the coolant flushed every few years in my daily drivers but I don't know how they do it. It seems to work since the fluid looks good after the flush but I've never watched them.

I only watched a few videos on youtube. not sure if they were instructions or sales.
none of the ones I saw actually changed it all out. but enough people would think they got a good change.

I too thought it must work well. but lol, they are crazy. I guess it moves enough to renew whatever corrosion package is in there so you get more life out of it. but not a cleaning for a gunky setup.