Good Morning, Denis,

"automatic small tank agitator??

That might be worth a try. Recently, there was a thread here in the Forum which discussed the idea of attaching a battery-powered vibrator to an old Yankee sheet film processing tank to achieve continuous agitation development. The Yankee tanks are otherwise notorious for uneven development (among other drawbacks), so it may have been a good idea. The device you have could work similarly if it has enough power to vibrate tank that's fairly heavy when filled with solution.