I let my son take the 07 nissan frontier out 4x4 off road driving. When I use 4x4 I try to not get stuck. When he uses it ,it involves splashing through deep mud holes and creating as much splash as possible. Now the power windows grind, and stick. Clearly the mud and sand has washed down into the mechanism.
What can be done to salvage the windows before they fail entirely?
All that can be done is remove the inner door panels to gain access the window regulators so that they can be cleaned.
Tester
While opening up the door would be the most effective way of not only definitively diagnosing the problem but expeditiously removing the mud, it’s not easy for the typical owner.
If you want a less challenging approach to try first, think about how the dirt got in there in the first place.
Using some wood shims you could space a few of them along the outside of the window to hold the gasketing off the window and facilitate flushing the door. Open the door and look along the bottom edge. There are drain holes to let water out. Make sure they aren’t plugged with mud or debris. Use a garden hose to flood the window and watch the drains. Muddy water should come out. When it runs clean, move the shims and repeat.