I did a search, nothing really came up. I am currently flushing my fathers old honda accord. To make life easier, we are simply doing the drain, refil, run, drain, and so on method. I removed the thermostat to make things a bit faster, and the heater is always on high. My question is, whats a good flush product? I have used the prestone flush in the past, and we have a bottle of Zerex Rad cleaner thats in there now. Unfortunately, this cooling system is NASTY...and the water is still draining out brown even after 7 drain and fills, with varying degrees of run time in between (sometimes a drive around the block, others a couple minutes of idling). The zerex stuff is in there now, and it says to accumilate about 3-6 hours of run time before draining. After this stuff is out of there, I am looking to try something else. Car is a 89 Accord, with about 163k. Just did a complete service on the thing, replacing the major cooling system hoses, thermostat, new gaskets, plugs, wires, cap/rotor, etc. Its running 10x better than it was, but the cooling system still looks like [censored]. Once its flushed, will be filling with G-05...as I have tons of it laying around. I would like to get this cooling system as clean as possible before filling, so any help will be greatly appreciated.