I use a water pick on very dirty adjustables. Usually with hot water and Listerine after a long hot soak and some Scrubbing Bubbles.
It gets messy because the high pressure sprays water everywhere and splashes a lot.
The pipe cleaner is a good idea to get the nooks and crannies. Many "stuck" adjustables are only ceased up under the adjustment plate. Those four tabs that actually raise and lower are where gunk can cement in place over time.
Pipe cleaners are great, they can get in all the little nooks & crannies. I used them the same way when I got my Fatboy. I was even able to get them down inside the handle to clean when I pulled the silo doors.