The typical way I was taught in my days as an administrator was to use groups for file access rights. All that would be needed to remove an account from accessing the files was to remove them from the group, which in itsself is a quite speedy process. There is also nothing preventing you from having just a single account in such a group. The group access rights can be removed by some background process then after the last account from the group has been removed. Still, removing an account from that group will immeadiately keep that account from accessing the files. Hope that will help you in the future. Cheers!
"I had the right to remain silent, but I didn't have the ability!"
Ron White, Comedian