Delete old notifications

Hey...

I have 5 pages worth of notifications/subscriptions. I tried to select the last 2 pages of those in "Type" (which checked all the boxes on the notifications), then I click on drop-down menu to get "Delete" and hit "Search" (assuming it is in place for "submit"). It did not delete the old notifications. 

I do not wanted to go and individually drop each notification/subscription every time. I wanted to delete them all en masse.

Thanks.