No, it really won't make a difference. The steroid is in the blood in trace amounts.
And don't say that the cleansing stuff is too good to be true, there are cleansing programs that work (that take longer than 5 days) and there are also next-generation masking agents that can mask a steroid if you ever to get tested.
I am sorry, I don't know where you can get them, maybe PM veterans, but I know they exist because World athletes and IFBB bodybuilders use it.
EDIT: I read the post about your friend said wrong I thought he said that 3 shots is the same as the whole 10ML. But apparently he said that 3 shots stays in the system as much as 10ML, which IMO is still wrong because the smaller the amount the less "traces" will be found and the less likely it will appear on a test.
That is like saying some who shoots 2 shots of deca will have the same amount of traces in the body for same amount of time as someone who shot deca for 12 weeks. It doesn't add up.