The fewer chemicals you expose the hair to the better, but if you do find the need to perm or reposition the hair you are better off allowing it to air neutralize for 24 hours (after rinsing the perm solution out of the hair) rather than using the neutralizer that comes with the perming kit. Skipping this step and allowing oxygen to perform the same function will save some wear and tear on the unit, and this is especially important with hair that has already been subjected to so much processing. And as rscout mentioned, make sure you use a mild perming solution.