eek !
soapy water tends to drown them becuase they breath through their 'skin' and soapy water with low surface tension covers them with a film of water wich blocks out the air, where as normal water forms droplets wich they survive ok.
no idea what soap does to compost though. maybe that crap eco stuff is ok ?
but apart from being a nuisance to you arnt they aearating it or something beneficial as that person above said, like worms i think they are useful for the soil. is it possible to totally seal the compost container ?
* meow rings the apostrophe police