No - absolutely not. Most of the aggregators even incorporate wording into their uploading system that says "I confirm I have not used stems, samples or components of previously released tracks in this upload" They then even warn you that doing so means a potential removal of ALL your content. I take this as meaning that your own samples of stuff are fine, but if you lift a sample from a well known recording, you are on VERY dodgy ground. Having evidence of clearance would be suporting any takedown - but the hassle of uploading every single release again and losing all the stats and comments is a serious risk.
My own test is to use shazam on the section with a sample. If it identifies it, don't even think about it, because you can bet they will do the same test and Youtube certainly does. Sample packages are safe as they're licenced for you to use and most are too treated and variable to be identified as 'that flute from the XYZ collection' for certainty.
If you use a vocal removed, or you remove the vocal from a track and stick in your voice, they will find you and they will ...... you get the idea.
