As most of the people have said,they never really go away,but I have found that the worse time is just after entering IMC,especially if being vectored and climbing
I had a bad expierence a few months ago with that->was vectored left and right a few times within about 20-30 seconds while climbing, just after entering IMC and I got a bad case of the leans
I just kept concentrating on the T and within a minute or so it had passed
Just keep a cool head and trust the instruments (and your vac system
) and it usually passes!!
C