I've done it, and to be honest, I don't think I ever will again.
I notice size gains start to really slow at about the 5 or 6 week mark, particularly so if I've used an oral kickstart, and using the oral for the full time (I think it was 8 weeks) didn't really impact that at all.
So in my mind it really just worked out to be more of a stress to my system for not really much more of a reward. (I mean we all like to tell ourselves that orals aren't as bad as people say, but depending on how you fared in the genetic lottery you might very well be doing some damage.)
Now, I've heard that when the myostatin upregulates and the gains slow down, apparently switching to mostly dht compounds can mitigate that. With that in mind, I suppose maybe you could do 4 weeks or dbol, give it a couple of weeks then hit 4 weeks of var. That might keep you gaining.
But I dunno, I don't think I'd run an oral for longer than 6 weeks.