Would certainly work as a cheap flush oil. I would say if it's only for a week and you're not planning on thrashing it. It'd flush the car out quite nicely.
On another note 10litres in the v8?!
Might Have to do some reading. I was told 4.5 for my v6. Best check that! I need a v8A litre a cylinder is the normal guideline for most cars. The s4's have a bit more, takes just over 9L
i would agree dont do it and as for the chain rattle although it seems bit of a characteristic of the engine mine used to do it a bit and then started running bad and after stripping it down we found 2 broken guides, its all done now and no longer rattles