Spray WD40 [through the straw] till you're bored of spraying, then soldier on and keep spraying. If it works wait a day for the solvent (yes, wd40 is a solvent) to evaporate the follow with a proper lubricant like triflow or chain-l #5 . These shifters are rather robust, burning a $4 can of wd40 before you write them off seems like a lot of potential reward for not a lot risk.