Depends on the balance of deep breath and breath hold. At the end of the day if the overall air exchanged is greater than necessary to maintain balanced CO2 levels, for example if you are deep breathing and pausing in between but not long enough to offset the amount of air exchanged, you could still be driving a net decrease in CO2 levels. However if you are breath holding until the urge to breath arises, which is driven by rising CO2, then yeah you are probably offsetting the effect of the deep breathing.