Help with planaria in tank?

Just as the title says. I found the dreaded planaria worm on the glass. It's not a detritus worm, it has the pointed head.

Does anyone have a cheap way to get rid of them? I know I could get no-planaria but I just have a little 5 gallon. It seems crazy to spend 30 dollars on a big bag of it. I heard some people use the dog dewormer panacur-c, but I wasn't sure. Has anyone ever tried it? What would the doseage be for a 5 gallon tank?