Been a few days now and the sluggishness in the keys has for the most part disappeared. Only the space bar and P key remain a bit slower in response, though not so they become problematic. Typing this I'm thinking I should just clean my keyboard, something I've never done before but that shouldn't take more than ten minutes. You just pop out the keys and wash them and wash the keyboard (with cloth, soaked in water, no water just as is). Due to various procrastinational reasons I suspect I'll just keep using the keyboard with these minor deficiencies though, in the long run the sluggishness will probably wear out completely.
Until next time I spill a cherry coke on my keyboard! And if you're wondering, this post has been lying around unposted for a while, thus the late date. Cheerio.