I could see you doing a couple things…
First, if running Windows 10 1709, you can use attrib.exe inside of PowerShell to unpin all the files. That revert all files to online only copies (the cloud icon). This only works in 1709 or later as the file attributes don’t exist before then.
Second, there is a registry hive that is created when a user has their account linked in OD. You could try blowing away the entry for the business account. The registry is here if you want to try and play with it. I just tried it. I think it worked, but I have autoconfigure set up, so i think it just set my account up because I started it. I suspect though that this would work.
Then, you could try deleting the run reg key so that it doesn’t auto start for the user if so desired in this location, Computer\HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Run.
I hope this helps a little.