BUG bomb use?
I suggest bombing and leaving the boat sealed to really fumigate. Then a strong anti bacterial cleaning occurs to remove the residue. take your cushions and otherwise and either use a local laundry to wash out soak and air dry at home. However, I partially agree with the poster who likes the spiders. Typically, a really good cleaning of the boat will eradicate the bulk of your bug issue. I'm more concerned with mold, myself.
Zeehag has a good point. I could've sworn I saw a key west cockroach wearing a backpack as he made his/her way across our companionway