Squeegee

Print yourself a custom squeegee. An array of sizes here give you a degree of freedom, but if you need a truly custom length, just ask. Just print a handle and then the length you need.

No special materials needed. Choose your favourite.

This is designed to fit Unger squeegee rubber, which is available worldwide.

https://www.ungerglobal.com/en/pro-squeegee-rubber

I've just noticed that Thingiverse shows the rubber holders as upside down, so they'll need flipping before printing. Obviously that won't print like it is.