SQL 2012 :: Script To Remove Any Foreign Characters From Table

I have a table that is riddled with weird characters. So far I have found an escape character for PDF files and a trademark sign. These characters are crashing my SSIS packages. I am able to remove these characters with an update script...

Update TABLE
set LEAD_NOTES__C = Replace(LEAD_NOTES__C, nchar(65533) COLLATE Latin1_General_BIN2, '!');

Update TABLE
set LEAD_NOTES__C = Replace(LEAD_NOTES__C, nchar(1671) COLLATE Latin1_General_BIN2, '!');

This works fine, but my question is...

I would like to write a script that removes all foreign characters with the exception of the normal characters like (@,#,$,%,etc). I need a dynamic process that handles this so I am not losing time sifting through over 20,000 rows of data and changing my update script to remove a specific column. Although this method works, I would prefer a dynamic query. I intend to wrap this in a stored procedure that loops through all columns in a table (as parameter).