you propably know all this already, but here goes:
the key is to crouch B as soon as he teleports behind you. the problem is: his teleport and crouch B are so fast that you can't react fast enough to crouch B before him.
choose a character that 1) has a fast crouch B. 2) can follow that up with a combo.
Benimaru is the best to do the job. and if you already know how to use Duo Lon himself, that would be even better (I don't

).
with Beni, if Dou Lon jumps, you will need to do a super jump if you want to counter him in the air (whoever higher hits the other). a small jump D won't work against his jumping D. always keep that in mind.
of course, the combo to use here is:
crouch B .... qcf B ..... qcf B ...[cancel]... qcf A (DM)
another option is to use Iori. the combo is:
(optional ->) crouch B ...... crouch A ....... [qcb A] x3
I always use these two. I mainly keep Beni for him, but if he couldn't finish him off, I bring in Iori. sometimes that works (depending on how good I play). I hope that helps.