Hey man, I will do my best to answer your questions.
I think the difficulty here is that because the compounds you ingest end up converting to other physiological substances once ingested/digested etc, its difficult to put a specific timeframe on their 'clearance'. Now, as far as you are concerned, that MAY be a good thing. In other words, if 4-andro converts to test, 4-andro itself isnt detectable, at least not in the sense that the hormone levels 4-andro impacts ARE.
There may well be more spohisticated means of testing for these compounds, or if not them specifically then hormonal 'red flags' indicating their use.
Sorry I cannot give you a black-white answer here, but maybe you can get a sense of whats generally involved in their use/physiological conversion?