If you got most of the excess off b/f it dried, I think you can salvage it. I've done that on my workshop wall WIP, and gone back in later and brushed w/vinegar (and as always my trusty screwdriver) and was successful. In fact, there are some spots I haven't wiped yet, but expect it to come off. However, if you slathered it on heavily and left it, it might take a scraper of some sort. Whatcha got to lose - take an electric sander to it and try it, if scraping doesn't work.

I'd give it a go like Slow said... what do you have to lose? But please do remember to wear a mask and not breath the dust into your lungs