Electrolize salt (NaCl) water without a proton exchange membrane is more likely to produce NaOCl. You need the membrane to keep chlorine and sodium hydroxide from combining to form bleach. The membrane may be made from a polymer which only allows positive sodium ions to pass through it.
Saftey note. The whole process also creates dangerous potentially deadly chlorine gas if not vented properly.
Its probably safer and cheaper to buy your sodium hydroxide from a commercial source as the producer is likely able to capture revenue from selling the sodium hydroxide as well as chlorine, and hydrogen that are made during the process, while buying their electricity at lower than residential rates.
Edit, I am not sure what will happens to the sodium ferrocyanide. The worse case is it is also broken down, and that at above room tempurature, cyanide gas will evolve at the same electrode as the chlorine gas, underscoring the need for proper ventilation.