I bought a cheap mini screwdriver set for cleaning up models and perf boards, but their handles weren't very ergonomic for prolonged pushing and shoveling with my bare hands. I ended up wrapping the handles with old socks, which didn't work quite well either.

These round headed handles fit around the smaller mini screwdrivers/ice pickers in the set, with 4mm diameter metal casing.

I've allowed for 4.5mm in the central shaft it should be easy to push the tools through.

The ice picker tool is very good for poking the plastic out of the perf board, while the flat-head screwdriver is good for scrapping the support off the printed models where other tools can't reach.

The central shaft in the uploaded STL file is 4.5mm. For larger screwdrivers, you can scale it up accordingly.