Hi Bernadet,
Yes, this is valid, and is the canonical way of doing the correction. It was proposed by Tom Nichols some time ago, and if you search the archives you'll find the steps there. I can't recall if Tom's original email to Lisa (the 2nd author of Licata et al, 2013) went to the list, but there is for sure an email in the archives (this one from me) in which the exact steps are outlined.
However, this was in 2012. Now the method has been implemented in
PALM, which does the correction on the fly, without the need for custom scripts or to save files to the disk. You'd just enter each IC as one modality (with its own "-i"), and use the option "-corrmod". The remaining of the syntax is very similar to randomise.
The paper that describes the method in complete generality is currently under review.
All the best,
Anderson