The next time you get the extremely bright idea of using dry-erase crayons on your windows and make a huge rainbow and allow boys to practice writing B on another one keep this in mind.  “Write-on-wipe-off” is purely figurative language.  It merely means that it will “wipe off” more easily than, say, acid etching.

It would be prudent to test an area first, or, at the very least, refrain from bragging about your brilliant resourcefulness in discovering a white board already in your school room that takes up NO valuable wall-real estate.

That being said, PLEDGE multi-surface spray cleaner (the kind you buy for electronics and stainless steel appliance polishing) melts the stuff off like magic.  Apply once to dissolve all and smear it around.  Apply a second time to remove.

In the event of an entire window covered with Wartburg castle and little squares in all the open areas colored in to make the whole thing look like stained glass; go buy more-lots more!