If you don't want to do transactions, you can set it once when you open the connection and it will remain at that setting until you change it. So just do:
connection.BeginTransaction(IsolationLevel.ReadUncommitted).Commit();
Probably not the best for your specific case, since you are opening the connection, using it, and throwing it away, but I wanted to put this answer in for anyone with a longer-lived connection.
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