I used 3m body protection tape. Stuff is tough as hell, but water spray is tougher.
Fwiw, even seaplanes with metal props suffer from water erosion. You can pretty easily destroy a nice (and expensive) Hartzell blade in a short time by just plowing around in the water at mid rpm ranges. The erosion is so bad it can literally make pinholes in the leading edge of the blade. Many have tried leading edge plastic tape on those too, but much like my experience they learn the water spray through the prop will disintegrate the plastic.
Flying through rain is apparently a minor concern compared to seaplane water spray. But believe me, I would love to find a alternative to the stainless tape I have to keep replacing on my IVO. I love my IVO IFA, but I absolutely hate having to constantly replace the stainless tape due to cracking, lifting, etc.
However, if I weren't flying floats I would most definitely use the plastic tape.