I still think if it's a clog like mine was.. running "flush" through it does nothing. The "flush mix" will just go a different route around the clog. It will just not go through the EGR cooler/ heater core route.
If you put the car up on jack stands and look up on the firewall from under you will see two hoses going into the car. They have quick disconnects on them. I could NOT get those quick disconnects off. They were baked on or something. I just took the hoses off the quick disconnects using a remote hose clamp tool...
http://ecx.images-amazon.com/images/I/51TAPZdWqTL._SX522_.jpg
Also a tool to remove the hose itself helps ALOT.
http://www.ricksfreeautorepairadvic...ads/2011/07/Lisle-80200-hose-removal-tool.jpg
Once the hoses are off from the quick disconnects you can hook up clear home depot hoses to them. I just pushed the clear hose onto the quick disconnects and it was tight enough to not have to use clamps. I can't remember the hose size.. 1-1/2" maybe? The tubing was like 6 ft long so I could bring it out from under the car for easier hook up to water hose.
Then I hooked up a water hose to the clear tubing via duck tape... and turned it on.. I had the other side of the clear hose going into a bucket so I could see what it caught coming out. I also reversed the water hose and flushed it both ways a couple times. The output I always had going into a bucket to catch what was coming out.
Once I was ALLL done clearing the heater core out I pushed the tap water out just using my mouth pushing air through the hose..
Then I pushed distilled water through the core to get rid of all tap by pouring distilled water in the hose slowly and pushing it with air pressure using my mouth.
All this cost me like $50.