It may seem strange but have you considered using headphones to practice through, finding a level that does not trigger the tinnitus?
I have permanent tinnitus and find that listening to music can help relieve the symptom. Also having this symptom continually means that the brain does sometimes filter out the whistling - a skill not possible manually.
Saw The Manfreds last Wednesday, one word EXCELLENT.
Paul Jones can still teach modern frontmen what it's all about.
The band - Paul Jones, Tom McGuiness, Marcus Cliffe, Mike Hugg, Simon Currie and Rob Townsend.
Cracking night.
Welcome Simon68.
I have found that the online tutoring can be very useful and hooked up with the Scott Whitley and Scott Devine sites. It may not replace face to face but it has helped me exile one or two bad habits.