Once a settlement of sorts is established, the astronauts returning from their ESA (Extra Settlement Activity) would have to go through some kind of isolated airlock or other small structure where either a water or air hose (probbaly the latter, unless they've gotten really good at recycling) gets the dust off.

Would "disposable" lunar suits be a possibility, or way too expensive for now?

Or perhaps we are taking the wrong approach: How about covering the immediate surface area with plastic to keep the dust down? I know this won't work for astronauts doing long ESAs, but if they have to be just outside the settlement, they won't have to bother with cleaning off every time they come back in if the dust is kept under wraps, literally. And I assume the science team will have already done a thorough geological analysis of the base area, so no need to study it or dig it up by then.