Ok, so the names can be very confusing because they’re very different in my language.
Acid chlorhydric is indeed hydrochloric acid. HCl.
What I called soda is indeed caustic soda, or sodium hydroxide, NaOH.
Bleach for me is also sodium oxychlorid, NaClO.
The first 2 are meant to dissolve things. The third is disinfectant. Never use bleach with an acid, because it makes Cl2 which is a deadly gas (used in ww1). But apparently you know how to take safety precautions, which is good.
I don’t know for where you leave, but the only drain cleaners I ever used where based on caustic soda. You don’t always need it to be gel form. The gel form is meant to stay longer while falling along the pipe and is safer for the user because it doesn’t splash. To my limited knowledge, consumer drain cleaner will usually make the soda less dangerous or smell better, but also usually less concentrated.