I'm not much of a Trout fisherman, and have no experience with wading staffs. However, I can offer a little advice.

I used to be one of those crazy nuts you see running around with a metal detector. I even had a waterproof unit, looking for jewelry in swimming areas. The unit I had was a diving model, and you could shorten or extend the main shaft quite a bit. However, that shaft would get some grit in it, and seize up. The easiest "cure" was to twist and pull the shaft while submerged in the water. If it really got gritty, remove the lower shaft from the upper completely, and rinse it out.

That might work with all y'alls collapsible wading staffs....