I once pulled about $12 in loose change out of a trap, boy was the lady happy to see her gold diamond ring again. Tee shirts, knickers, wash cloths … I still have no idea how those five 2x4’s got to the bottom of my septic tank.
Two three gallons of boiling hot water with dish detergent is a big help keeping grease and fat buildups from accumulating in the inlet baffle … I’m sure that would work in the general case as well.