For want of a better place to log how to get at the dishwasher pump next time it gets stuck with a tiny piece of plastic blocking the impeller, I’m sticking it here.
In case it helps anyone else it’s a Bosch Classixx (no idea what model no, bought about 2004 IIRC). Here are the steps:
* Turn it on its side (right hand side looking at the door – the one nearest the programme dial)
* remove the bottom (remove two screws and need a flat screwdriver to prise it a bit) – it has an earth wire attached, so don’t yank it completely away
* Don’t lose the bit of polystyrene from the anti-flooding switch!
* Follow the drain hose (that goes to the u-bend under the sink) back to the pump
* Squeeze the clips and rotate the pump, it’ll come off fairly easily
* remove tiny piece of debris of some sort.
* Put it all back together again.
Is this the modern equivalent of going out hunting sabre-tooth tigers? Probably not :)