Pontiac Repair: Oil in Radiator, liquid laundry detergent, quality radiator

Question
1) How much total liquid should drain out of my '97 Grand Prix SE radiator. (I think it's a 3.1)
2) It is likely I put oil in my radiator instead of where is belongs.  I know...BAD.  When opening the rad. cap, the visible liquid is a slimy,light brown in color, and sort of aerated.  There are no symtoms of anything else.  So far, I've drained the radiator once (after engine ran about 8 minutes) and about 1 - 2 gallons of orange anti-freeze came out slowly.  Nothing oily and brownish.  Then I added about a 1/2 gallon of water thru and drained again.  Not much difference.  Next try I put in about 1 cup of mild liquid laundry detergent and added a 1/2 gal. water (all it took) and ran the car about five minutes.  Drained it again, still just a couple drops of oil and the 1/2 gal of water.  Poured another 1/2 gal water to drain thru.  
Questions:  Do I need to remove the thermostat?  Can I run the engine while flushing the radiator?  I have a couple quarts of engine flush that I haven't used yet.  Is the water that's draining out just from the radiator itself?  Should I get the engine a little hotter?
If you have immediate answers I would really appreciate it.  Feel free to contact me by phone.  (206) 356-3022
Thank you very much!  (And yes, I should have been paying MORE attention)

Answer
hello michelle i would recommend draining all of the water from youre radiator and rinsing it out to make sure all the soap is removed.then refilling youre radiator with water and a good quality radiator flush.following the instructions on the radiator flush bottle and the putting a good 50/50 pre mix antifreeze back in.you have to run the engine until the temp.gets up and the thermostat opens and allows the coolant to flow thrrough the engine.i would never recommend using any soap in the radiator this could damage youre engine severely.youre radiator and engine should take about 2 gallons to fill completely.there is also an air bleed off on the thermostat housing or on the engine somewhere to allow the air to bleed out of the coolant system when filling.good luck