I was going to do this on my Swift,but decided against it as there was a long waiting list from the preferred repairer,and its very expensive.
I decided on using Fernox central heating system cleaner ,sitting in rad then power washing out. I then used "alumaseal" for any small leaks as its a low pressure thermo siphon system. Luckily my radiator was servicable.
The name of the repairer escapes me but they are in the back of the "automobile" magazine.
Steve Gray ,AC Heritage may also know having prepped his car for Peking Paris.
Graham