make sure the seals are put in the correct direction so water and dirt cannot be pushed in easily and dnt pressure wash the linkage directly. maybe try some good grease as suggested by KX02, i always use a half/half of belray waterproof grease and honda molybedenum 60 paste. the moly keeps bearings from rusting even if water gets in. i havent had anything bad to say or heard about from either all balls or pivot works, but maybe a oem kawi bearing would last longer. also if the bearing is a roller pin type and your engine has a loose bearing or vibration it will kill that roller bearing in shock real quick. ktm had same problem with lower bearings until they changed to a heim type bearing with no rollers and a tighter fit. so check your crank bearings and engine mount bolts.
also check linkage , bolts, and the bell crank where the bearing go in to make sure they are all straight and the bearing holes are round. i had a yz the the linkage got bent on, made the shock feel like crap and the bearing to get sloppy in a few rides. i think something besides the bearing is the cause.