The percentage of O2 in the blend isn't the issue its how its filled. If the gas goes into the tank as 32%, then there is no reason to get it O2 cleaned.
If you buy 22% and they put that extra 1% in as pure O2 (partial pressure blending), then you need O2 clean tanks.
So, if they have a bank of 32% or something like that you are fine. I did run into one shop that would not VIP a tank with a nitrox sticker on it unless they also O2 cleaned it because they claimed someone might try and partial pressure fill it and therefore they must do this to nitrox tanks. I didn't know better at the time, but I do now. Shops selling that sort of line are just trying to get more money from you.