Yes, Engine Flush and Ceratec are two different products.
I used the engine flush and then used Ceratec 
Basically, u go for an oil change, before draining old oil u pour engine flush in it, start car and let it idle for a bit. Then u drain old oil+flush. and pour in new oil+ceratec. thats it.
Note: Ceratec must be used in specified quantity only. The remaining can be poured into gear oil if u have a gear oil change due. Also, Ceratec is good for 50k kms (I think, somewhere near that) so u cant use it again and again.
Its purpose is pure lubrication and helps reduce wear and tear inside engine considerably.
Do NOT think that ur car will become a rocket or something similar, the benefits are inside the engine and not noticeable until u drive a 100k kms or so, upon which health of engine will show u the benefits.
That being said, after Ceratec i did notice car idling was smoother.
Peace 