My ultrasonic cleaner sat in a box for 6 months, now I'm kicking myself

I picked up a secondhand ultrasonic cleaner at an estate sale for like $40 and let it sit in my garage because I figured it was just for jewelry and gun parts. Last week a customer brought in a Pentax that had decades of gunk baked into the shutter blades and all my usual solvents were making it worse. Out of desperation I filled the tank with some lighter fluid and ran the blade assembly for 90 seconds. I could not believe the difference, the blades moved freely after being stuck shut since probably the 80s. Now I'm testing it on old lens helicoids and even some circuit boards with a low heat setting. The whole time I was hand scrubbing with toothpicks and cotton swabs like some kind of caveman. Has anyone else had a similar moment where you finally used a tool you owned forever and realized you wasted way too much time doing it the hard way? I'm curious what other cleaning shortcuts people have found for sticky aperture blades because I want to make sure I'm not missing something else obvious.