You have to be carful with TCut. I did the same with some on another bike a while ago.
Stupidly, with the bike on the centre stand, i put the pot of Tcut on the tank while i was finishing off the fender.... Well you can guess what happened..
I had to take all the fairings off, not only had it spilled all over the black plastic but got into the nooks and crannies everywhere. I was still finding the stuff a couple years later!
But yeh, that textured plastic is the worst stuff. It solidifies in the valleys of the texture.
Wet the area with plain water. use an old toothbrush and mucoff (or an ecological washing up liquid) to gently scrub the area in small circular motions. Keep it from drying out until you have done all of the area.
Then rinse off with a hose. You may have to do this a couple of times.
If the plastic is still looking dull or whitish when it dries, then you have two options.
Buy another bit of fairing OR commit to using a plastic dressing spray.
If you do use the spray then you will have to accept that you will have to reapply every now and again and may have to put it on some of the other same surfaces to match them in.
I use the Simoniz one, i think its called 'back to black'.
I spray it onto a clean lint-free rag and apply it that way, instead of spraying the stuff straight from the tin.
That way, i can control where the stuff is going.
Its pretty pernicious slippy stuff (i think it contains silicone) and if your not carful can get onto your seat.
Anyway, hope that is of help to you.