Since your TD is both oil and water dispersible I would say your best bet would be to stir some into glycerin and leave it for a few days. That is what the Wilton brand icing whitener is made of, TD and glycerin in a little bottle with a drip cap. You only need a little bit, TD is a very powerful whitener. You don't say how much you used, but really a small amount is all you need.
There was a post around here not too long ago where someone experimented with putting TD into the oils before adding the lye and putting it in (pre-dispersed) after trace, and they got much better results using the TD up front.
There was a post around here not too long ago where someone experimented with putting TD into the oils before adding the lye and putting it in (pre-dispersed) after trace, and they got much better results using the TD up front.