DIY Water sensors, what kind/type wire are you using for the probe part?

I made a couple of DIY water sensor using the monoprice contacts. I initially used an old USB cable that I spliced to use as sensor probe but I think it could be better. I ended up twisting a couple of small screws on the tips so that there will be some weight to it and make sure it keeps contact with the surface/floor.

Looking for other types I can use that has some weight to it and maybe flexible at the same time.