It depends how you define "remove all local NTFS permissions". If you mean to set the permissions to their default then some users may not be able to access files there were able to view before along with other files which shouldn't be viewable being viewable. That is only if you are meaning to set the permissions to their default.
If however you mean to strip all permissions from all users then nobody will be able to view anything.
No matter what you can always take ownership of a file as an administrator or member of the administrators group. Doing drive recoveries I work with files that were created on another computer and with users I do not have. As the administrator of my computer I can go in and take ownership of the files and folders the do what ever is needed.