I would recommend you to do it only if your blank webcomic gets big, like a known phenomenon. As long as you are upfront about how those are only blank pages and nothing more i would not see a problem if they choose to pay. You can even name it "don`t participate in this Patreon", as a tribute for your blank webcomic.
Now seriously, we should think about how far do we want to take this experiment. If you get paid a lot, it may unleash a trend of blank webcomics trying to make it big without content. And that gives me mixed feelings, because on one side, i thing it would be a hillarious story/urban legend if it happens. But on the other hand....I don`t want webcomic pages full of blank comics.(and pages creating a gente called "blank" to fit these)