Please note that I'm not a certified mechanic; I don't play one on TV, nor did I stay at a holiday inn last night...
Can you put a screen (like 1/4" mesh) in the bottom radiator hose opening that would prevent this bolt piece from flowing into your water pump? If so, then maybe this size (or similar size) would also allow for sufficient water flow, and then you can just leave the piece in there. Just a crazy thought...
Or you can mount your car on a rotisserie and flip it over to if it'll come out of the top hose hole
