Hmm, yes, that's a little more complicated than first appears... The first part is easy - a piezo will work with any string because it picks up tiny changes in pressure due to the vibration of the string/bridge...
Contact mics like the Ehrlund (shameless plug there!) will also work on any acoustic body because, well, they're mics...
Magnetics, however depend on ferrous metal in the string to disrupt the pickup's magnetic field and different double bass strings have wildly varying amounts of these metals, so you'll get wildly varying amounts of signal.
Innovation say that none of their strings will work with a magnetic pickup because they use synthetic cores, and this is certainly true of the slap and rockabilly strings; though you can get a bit of signal from the jazz and orchestral sets because there's more metal in the windings; some people find it's enough, but we don't like to guarantee it.
Hope that helps!
Cheers,
Daf