Does anyone have a source for positive control solution for guiac-based fecal occult blood testing?

For our staff competencies interpreting the guiac fecal occult cards I would make a positive and negative fake “patient sample”. The negative sample was just dirt mixed with some water. The positive sample was dirt mixed with water and few drops of iodine. 
Worked great! We used Hemoccult SENSA.  I always joked that my career had peaked when I started making fake poop samples! 

Lorena
We have used chocolate pudding and mixed in a few drops of hemocue control.  This has worked well for training as we could load the cards days ahead of the training date. 

Chocolate pudding recipe, or I have used Chocolate agar, which works well too.

Hello. We use old CAP samples.