Hi,
Based on my experience I just do not think its needed. Some of those needles that seemed to stick when viewed outside a carby did not stick later after a bit of a fuel soak and in the carby with a very small head of fuel abpve it.
Norm,
How many have you had that caused an actual problem in use? My score is 0 out of 2. I thought most of yours were flooding. As I said before the transparent tube seems to help as you can see the bubbles move and then stop if all is OK.
All the best
Jeff