Sounds like the video was an acid/base extraction for extracting pure cocaine (although it should be noted other alkaloids would be extracted along with the cocaine, so depending on the cut will determine the final purity) from cut cocaine. If done with proper lab technique, your reagents would not contaminate the final product, but if done improperly you could end up with contamination from the solvents used or leftover solvent traces. If you don't have any chemistry experience, proper kit or good quality reagents, it would probably be unsafe to try and follow that sort of procedure at home.