Oxalic Acids in the Rhubarb-leafs can be used for:

• In household chemical products such as Bar Keeper’s Friend, Zud, some bleaches, and rustproofing treatments.
• In wood restorers where the acid dissolves away a layer of dry surface wood to expose fresh material underneath.
• As an additive to automotive wheel cleaners.
• As a mordant in dyeing processes.
• Used in platinotype, the early photographic Platinum/Palladium printing process.
• Vaporized oxalic acid, or a 6% solution of oxalic acid in sugar syrup, is used by some beekeepers as an insecticide against the parasitic Varroa mite.
• As a rust remover in such applications as automotive shops and for the restoration of antiques.
• As a recommended surface pretreatment for stainless steels (surface etch) before application of solid metal or polymer self-lubricating coatings.
• For polishing stones and marble.
• Used in the acid treatment for destroying warts