Pogle Platinum has its own Rubbish Bin, which can be used to remove any unwanted Users, Projects and individual items, like Platinum Lists and Notes. Each User has their own Rubbish Bin.
You can move an item to the Rubbish Bin by selecting the "Remove
.." menu-option for any Vault item. Or drag the item over the
Rubbish Bin icon, directly. To view the contents of the Rubbish Bin at
any time, simply click the Rubbish Bin icon; the icon will remain
flashing
to indicate you are looking
at the contents of your Rubbish Bin.. To recover any item simply click
on it. It will automatically be returned to its original place in the
Vault.

The Pogle Platinum Rubbish Bin is not the same as the SGI dumpster. If items have been deleted using the SGI desktop, then the "Desktop > Empty Dumpster" Toolchest menu must be used to regain space.