I agree with Sting. While one could theoretically speed the process of removing excess nitrogen by breathing a gas with less nitrogen that regular air, that assumes that you have not already blown a decompression obligation. If you have, then you risk having nitrogen bubbles in your bloodstream and the only real solution (excuse the pun) is a chamber ride.
If you want to use something other than air to speed offgassing, just as an added precaution, that might be okay. However, if your goal is to shorten your surface interval so you can get back into the water sooner, I would be very hesitant to do so. The tables assume one is breathing air on a SI and I am not sure how one might calculate nitrogen loading with a shorter SI and a gas other than air.
