It takes a huge amount of time and effort to clean out the cooling systems if you have had much intermix. I had my radiators hot tanked, flushed the systems many times, cleaned the aluminum tubes, hoses, changed the coolant several times, etc. etc. and I still have little bit of residue that show up.

Also, based on my experience, the concern with damage to the rubber hoses is overblown. I had extensive intermix in both the cooling system and the oil system when I had the problem back in 2008. We are talking thick sludge in both systems. After fixing the cracked head I have 7 years and 35,000 miles. In the time I have replaced a couple of hoses, but the majority of the hoses are original and have not failed.