Cabbage warts are VERY VERY contagious, so if someone wanted to 'pop' them and scrape them out at home, to disinfect the entire floor where it was done, to disinfect their hands, put betadine on the opening and bandage the foot up for a few days. Nothing worse than the entire kennel picking it up as well.
I had a bitch recently that had a cabbage wart which she picked up from a place that I left her there for a few weeks, she passed it onto her two kennelmates. I popped it and scraped it and squeezed out all the blood/gore then applied dressing to it and bandaged it. Hasn't recurred as yet and it's been 10 months now so must have been very lucky to have got it all out.

Definitely only to be done by an experienced person, otherwise best option is to take to a vet to do a proper job.