Negative Exact or Negative Phrase for Broad Keywords?

I've looked for an answer to this everywhere but can't find one, so thanks in advance for any help.

I have a list of negative keywords I've placed into an Auto campaign. These are keywords I'm using in a manual campaign for the same sku (I get sales from both campaigns and though it may seem counter-productive, it works). I have a few Broad kw's in the manual campaign. When placing these Broad kw's in the auto campaign's negative keyword list-is it better to use negative phrase, negative exact or both?