Think its been done quite often. Worth running some cheaper oil to clean it out?
So why do you think it is dirty and need flushing?
If you really want to flush it then use an oil approved for your engine with a new filter. Run it until the oil on the dipstick goes black - probably about 3k miles. Drop it out, replace with an approved oil and filter.
If you are really worried about it - repeat the above and change it when it goes black. Forever. That is the best protection a man (well, his engine) can get - but it is overkill.
Could do with Oilman's opinion here but IMO - a turbo engine would be better protected at the end of its service interval with fully synth oil than running with cheap (non turbo) oil on day one.
So no. I wouldn't put cheap oil in it if it was mine...
