It would be very easy to get rid of I think, not like a house. A boat cabin is a very confined space. Just seal up the hatches, cover up your food and water supply, and take out every panel and open and empty every drawer and cabinet. Then empty a bug spray can. The cloud will be confined and will go in between the keel stuff down low too, or you could start there.
If you just concerned about the bilge, pour some ethylene glycol down there. It will also prevent any water that you can't get at from freezing.
They may like the sweet taste, but they'll be dead fast.
that wont kill the eggs or egg cases. Boric acid left in nooks and crannies and any place they like to frequent will kill them all within one month. Easy clean up after a month you just vacuum or mop up the white powder