Radiator flush

There is no need to use distilled water for flushing the radiator. You will be draining it out anyway. Some may remain in the block, but it should not contain enough minerals to cause any problems, especially if you are using distilled water to top it off after putting in the correct amount of coolant. The DexCool contains additives that should negate the small amount of minerals found in most tap water anyway.

Is perhaps better to use distilled water because it contains no mineral content i.e. is less corrosive - I just use the ole hose and do a regular flush about every 2 years!

Can't tell you the quantity i.e. all engine cooling systems are not created equal!

Perhaps your owner's manual has the quantities!