Blackcatter

you may be right. The few times I have done it, I merely ran some warmish water (not boiling) from the hot water tap thru the mouthpiece fipple hole. Then I took some ice on the barrel, and using a tea towel, twisted. The parts disassociated. I found it useful to wrap a small amount of that white plumbers teflon thread sealing tape around the barrel - it stops things from sliding around too much.

Robin