Local Garage Coolant Flush

[Devildog1]

Going to have a local garage do my coolant flush/change and install a coolant filtration system. They say they'll hook up the machine and do the complete flush. Should they still run the distilled water through it or is the machine flush enough. Any other recommendations would be appreciated.

Thanks

[late_99_PSD]

The machine should be ok. I guess I'll beat everyone else to it but your the cat ec-1 coolant in it right?