Free Float Handguard

If your AR is dropped in the mud or rained on, how do you all clean under the one piece free float handguards like the DD Lite or Larue?

Im trying to figure out what is best for me between the Daniel Defense Lite and RIS II.

Hose it off, dry, lube.

Guns are not allergic to water.

Thats it huh! How do you get a coat of lube on the barrell under there just squirt it in there? Thanks for helping