In the Calys, they are pinned apparently because the scales are too thin for proper screws. The LWT Manix has no steel liners and is VERY thin FRN/FRCP... Might be part of the reason why.
My thorough cleaning: Loosen pivot, run warm water on the knife, brush pivot area with toothbrush and dishsoap, hit all points and crevices and proceed to brush the entire knife including scales, jet rinse with warm water thoroughly when finished, dry with papertowel, blow pivot etc. with compressed air, spray wd40 on pivot and blow excess off with comp air, dry with a fan or hair dryer, once dry- lube pivot and re-tighten..........This is also what I do on my knives WITH screws. Plenty sufficient. Of course I'd also prefer to have the option of taking it apart completely for various reasons but I can live with it.