There have been requests from fans in the past to send Disney sachets of mustard and mayo as a protest to WOY's cancellation. This has been done in the past to other companies and have sometimes been successful.
Personally, I do not approve of this idea for a number of reasons. 1) Postage costs. 2) Disney Getting annoyed. 3) The mess it could make. My alternative to this would be to have an image of a tub of mustard or mayo and based on what the fans, themselves, would pick, print out that image, write #SaveWOY on the paper somewhere and mail it to Disney, or even email it to them.
However, this project runs a huge risk of annoying Disney if enough people do this. I have put off this idea many times in the past as a result. It could go either way, it could annoy Disney so much that they start to disapprove of the SaveWOY campaign and its fans, or they could be annoyed enough to grant the fans a third season, maybe admire the fans' dedication.
This idea needs a lot of debating and should only be used as an absolute last resort as it could affect the rest of the campaign in a bad way if Disney fails to see the humor in it.