I thought that was good, because some crap can get stuck on a filter or something? I may be confusing this with someone else though..
I had some pretty nasty coolant, and had scale on my heads, intake, and a little on the block.. all over the lines too. But, none of this stuff will come out unless you take a screw driver to it, it'* that bad. So, I don't know how much some of those products will do, but since I have all that stuff off, I am not just going to leave it, because I am a new freak. But, you should most certainly run water through the system to flush it.. maybe not in the winter months where it dips below 0, but in the spring time..
'89 SSE - GX3 -190k, 155k on body - Back for another ride.