*Very* OT pronunciation help, please!

[cubfanbudwoman]

Hello, from a too-long lurker.

When my family & I visited England earlier this spring, being the big soccer/football fans that we are, we knew we wanted to see a match whilst there.  So we went to a Derby County FC match and promptly fell in love with the team (and I in love with Robbie Savage ;)).

So here's my pronunciation question, re: former DCFC manager Brian Clough and current DCFC manager, his son, Nigel Clough.  How the heck does one properly pronounce CLOUGH?

Does it rhyme with rough?
Does it rhyme with clock?
Does it sound like clog?
Does it rhyme with slow?

Help, please!  

I know there is a recent film -- Damned Utd -- about Brian Clough, but it's not been released in the US, so I can't hear it being spoken there yet.

Siriusly Snapey (and Savagely) Susan