Altecs Red Wine Remover is THE stuff.
It does what it says on the label, I think its a kind of peroxide tho it doesnt say that on the label, it smells like ladies hair dressers kind of bleachy.
Made me a hero time and time again, but you must rinse it out afterwards as it keeps on working and lightens the carpet. Use with care on Chinese rugs as it can take the dye out of the fibres.
Dont smell it, it stinks like a strong kind of ammonia, something like smelling salts used to.