Detecting && Deleting Duplicates In Batch Vs Proc

I know how to detect & delete dups/or >dups in test with a select clause, this works fine in a small table, but if the table has a million rows say, it sounds like a proc would be faster:  my question is:  How do I display those rows in a proc for detecting what the problem is.  The print stmt. doesn't seem to work and I wondered if I had to go through the process of building an output stream.  The proc creates okay but I'm stuck after that part.

thx

Kat  -- very rough code below

 

SET QUOTED_IDENTIFIER ON
GO
SET ANSI_NULLS ON
GO
create proc dupcount
@count int
as
set nocount on
select categoryID,
 CategoryName,
 Count(*) As Dups
 from Categories
group by Categoryid, CategoryName
having count(*) >1

set @count = @@Rowcount
print convert(varchar(30),CategoryID) + ' ' + convert(varchar(30),@count) + CategoryName

/*set @count = @@RowCount
IF @count > 1
print convert CategoryID, CategoryName, convert(varchar(30),@count)*/