So glad to read your question Hugo and Greg’s response. I too feel that the only sympathetic isolation I can achieve is on a very low pedal tone and I mean low because I’m a bass trombonist! I also wondered if I should continue if the process isn’t 100% pure. Nice to know the answer is yes. Looking forward to thousands of repetitions of the low pedal as more of the pure process slowly makes its way into my playing.

Yep, stick with it mate. Just let go from all instincts and habits and just observe the RESULT. It will develop over time. Cheers, Greg