Die Sonate hat sich gewaschen

Having realised from Radio 3's Beethoven marathon that I find it hard to get tired of listening to the great man, I've been listening through as many of his works as possible, starting with the early ones. So far I've heard 2 symphonies, 6 string quartets and 2 piano concertos. I've also been going through the piano sonatas, using the complete set still available on demand from Radio 3, recorded by Artur Pizarro. When I reached the eleventh one, I came across Beethoven's own comment on it in the programme notes here. He wrote to his publisher

in colloquial German that 'Die Sonate hat sich gewaschen' - 'The Sonata has washed itself', which the great musical analyst Donald Tovey likened to the English phrase 'takes the cake'.

I would like to adopt this phrase for everyday use, not about piano sonatas necessarily as I rarely compose them myself, but knowing my knack for language, there is little chance of me remembering it even an hour from now.