I'm just glad I had a sender that I could test it on.
You could do a simple test.
Carefully remove the nut and lock washer. If the plastic standoff slips off easily you could disassemble the sender and then soak only the steel and float arm and sweep.
There is one part you have to bend slightly out to be able to remove the rheostat. But it also gives you access to repair the sweep like the how to shows.