You may do this at the most I believe to avoid anyone accessing the resource pool,
1. Change the resource pool setting to Freestanding. So it does not get linked to any Org Units and remains totally independent.
2. You can remove resources or efforts or change dates, so they don't reflect in any resource capacity.
3. Remove the access of all the users from it through the Configure Access.
All the above will at least ensure that this resource pool will not add up to anything in the application, for any capacity calculations, etc. and no one can also access it. It will be only visible at places but won't be doing anything. You may also rename the pool by prefixing/suffixing like '-Disabled' or so that tells users not to use this pool for anything. Hopefully HP will introduce disabling/deleting resource pools in future versions.
Thanks I've already done all that. I was hoping for a way to make them not visible. It seem like no matter what you do to prefix or suffix or anything there is still always a user out there that picks the wrong thing.