It is generally not recommended to use an ordinary household bucket as a sauna bucket for several reasons.
Firstly, sauna buckets are specially designed to withstand the extreme conditions in a sauna, including high temperatures, humidity and steam. They are made of materials that are both heat resistant and safe for use in the sauna. A typical household bucket is usually not designed to withstand these conditions and may melt, deform or release harmful chemicals at high temperatures.
Secondly, many household buckets may contain substances that can give off toxic fumes at high temperatures. For example, some plastics can release harmful fumes when heated that can cause health problems if inhaled. In the enclosed environment of a sauna, these vapours can be particularly dangerous.
Thirdly, using an unsuitable bucket could affect the quality of your sauna experience. Sauna buckets are not only functional, but also add to the atmosphere of the sauna. They are often made of attractive materials such as wood or stainless steel and can enhance the sauna experience visually.