I think this comes from how he writes his songs. He has a melody and blocks out the lyrics by singing whatever fits the melody. Sometimes it works out great. like in Jet "And Jet I thought that the major was a little lady suffragette" What the heck is a "suffragette'? But it works in this song Dustbin lid doesn't Just like 'salamander' doesn't in Getting Closer. Thankfully he came up with better lyrics for 'Yesterday' 'scrambled eggs baby how I love your legs' It just shows he works hard on his lyrics when he feels he has a great melody to work with.
A suffragette was a member of the womens 'right to vote' movement in the UK about 100 years ago or more. They were a bit vociferous and set in their ways. I agree with the 'dustbin lid' lyric - it stood out when I first heard it. I believe it is cockney rhyming slang for 'kid'. I guess the syllables in dustbin lid fitted better than kid but it is still poor.