Ideas that you might find useful in a garage or workshop

Ideas that you might find useful in a garage or workshop

https://youtu.be/WrDfhZ2h9og

Please may you provide some help?
At 4:00 I see two jars, one with lighter blue liquid labeled "ЛАΤЧНЬ" and the other with a darker blue liquid labeled "МЕДh" (not sure to have interpreted them correctly). What do they means?
What is the role of the ethanol (C2H5OH)?
Why washing the parts in sodium hydroxide after coating them with copper(II) sulphate?
Thanks for the video.

Composition for copper:
copper sulfate - 100 gr.
alcohol - 50 ml.
battery electrolyte - 250 ml.
distilled water - 150 ml.
The composition for washing:
alkali - sodium hydroxide

For brass, 1/1 zinc electrolyte is added to the copper electrolyte
Zinc Electrolyte:
add to battery electrolyte
pieces of zinc, leave for 12-24 hours. Then filter, add 50 ml of technical alcohol, per liter of electrolyte.

Thank you very much for your reply and for the composition you provided. But still I don't get the scope of the alcohol in the mixture.
Cheers.

Alcohol 50 milliliters