French Pronunciation

It's fun learning a language when receiving medical treatment! In the last year I've had practice!
Last week at the kinaestherapist I attempted to explain what I had learned from the internet about my arm injury / problem.  When she said that a lot of people have the same problem it seemed she wanted me to accept it as part of my age! 
Non, no, non!   I need my arm to carry logs...and here begins the lesson because she didn't understand my pronunciation of two homophones which are not pronounced exactly the same:
There is une bûche and une bouche!  The first is a log and the second a mouth!
When she realised what I was trying to say she was in hoots of laughter!
(In English I thought "Well, the French can't pronounce some of our sounds!")
She had me practising the oh as if to end with a wer sound then think of making an ee sound whilst pushing the lips forward and making the oo sound like at the bottom of the front teeth!
I had to do that whilst little electrodes created wonderful tinglles acros my shoulder blades!
Then there are other words that sound similar:
bu - pp boire (to drink)  
le but - goal
la boue  - mud
le bout - tip