Hydrochloric Scid 330g/L (HCl) also known as is Spirit of Salts, indeed commonly used for cleaning purposes due to its strong acidic properties. However, it's crucial to handle it with extreme care as it can cause severe burns and damage to surfaces if not used properly.

Here's how hydrochloric acid can be used for cleaning purposes:

1. Removing Rust and Scale: Hydrochloric acid is effective at dissolving rust and scale from metal surfaces. It's commonly used for cleaning rust off of iron and steel surfaces, such as machinery, tools, and equipment.

2. Descaling: In industrial settings, hydrochloric acid is used for descaling metal surfaces to remove mineral deposits and scale buildup. This is particularly important in equipment like boilers, heat exchangers, and pipelines.

3. Cleaning Concrete and Masonry: Diluted hydrochloric acid solutions can be used to clean concrete surfaces and remove efflorescence (white, powdery deposits) and mineral stains.

4. Household Cleaning: In diluted form, hydrochloric acid can be used for household cleaning tasks such as removing stubborn stains, mineral deposits, and mold/mildew buildup, although extreme caution should be exercised.

When using hydrochloric acid for cleaning purposes, always follow these safety precautions:

• Wear appropriate personal protective equipment (PPE) including gloves, goggles, and protective clothing.
• Work in a well-ventilated area to avoid inhaling fumes.
• Dilute the acid according to the manufacturer's instructions or recommended guidelines.
• Never mix hydrochloric acid with other chemicals unless specifically directed to do so by a qualified professional.
• Dispose of leftover acid and cleaning solutions properly according to local regulations.

It's important to note that while hydrochloric acid is effective for cleaning, there are also alternative cleaning agents available that may be safer and less corrosive for certain applications. Always consider the specific requirements of the cleaning task and prioritize safety when selecting cleaning products. If you're unsure about how to use hydrochloric acid safely and effectively, consider consulting with a professional cleaner or chemical supplier for guidance.