@kublai a bit tricky in this version. Beta3 will have a disable and unistall function.
Basically: If your /jffs/scripts/ directory was empty before you installed AB (if you're new to these custom scripts then it sure was), then delete all of them as well as the /AB-Solution/adblocking/ directory.
Now reboot the router and install AB again.
You can leave the /entware/ dir in your USB device. It will not do anything without the scripts in jffs.
I started from scratch this morning as my jffs partition was not even enabled so I have nothing to keep. I'll do what you suggest. Thanks again.