I have removed the pockets on my PP jumpsuit and have someone all set to re-apply them in the proper spots, but before I do...is there any special thread I need that will take dye or withstand the dyeing bleaching process without losing integrity?
You would need a cotton thread to dye properly- as polyester thread will not. As far as standing up to bleaching, dyeing, hard to say. What you may want to do is take a scrap of material and do with it what you plan for bleaching and dyeing and then match your thread to that. I'm not sure how strong an all cotton thread is compared to a poly cotton mix.