i use to get the donut effect too from WET jelqing, but i have stopped it by
1) I dont jelq straight from the base, I have my non-jelqing hand at the base pulling towards the pubic bone so there really isn't any loose skin to stretch out
2) I stop my jelqs right before the head. I never let the skin go over the head, b/c this is where most of the donut effect occurs
Every once in awhile you will still get a bit of loose skin after a session, but it should be noticably less