Some guns were not designed to be cleaned very well
My first semi-auto was a Russian SKS which was when they were going for under $100. The Russian SKS is a very well thought out semi-auto because in my opinion, I like the operation and disassemble more than the M1 Garand. I think the Garand is a fine rifle and far more accurate than an SKS, but the stripper clips and lighter ammuntion is better suited for WWII combat although it was not introduced that early. The AK ended the short adventure of the SKS much in the same way the M16 shortened the life of the M14. They were all very well designed and reliable firearms, but they were not modern enough for combat. One gun I have found that I still enjoy shooting and operating with is the FAL. The triggers on these guns are a little hard to drop in weight, and the mounts on them really need to be locked in place with something other than just a screwdriver. The .308 caliber will do a number on scope mounts especially exposing any operator failures to properly “lock it down”.
One thing that made me a fan of the DSA FAL I own is that it was designed to be easy to operate and maintain. I’ve heard many firearm instructors that I respect say that the M16 does not need to be cleaned as much as people think and lubrication is more important than scrubbing every spec of carbon off the firearm. I still enjoy cleaning some of my firearms just because I like inspecting the geniousness of the designs. I literally can clean and FAL with gun cleaning supplies like the Hoppes bores snakes. The Otis gun cleaning kits aren’t necessary on one of these guns and more appropriate for more complicated designs. The FAL is hands down the simplest battle rifle to clean.