To break a broody you are essentially trying to prevent her from maintaining a slightly higher than normal body temp. The broody buster cage does this by putting her in a cage with no bedding and air flow underneath to cool her underside for a few days. Standing on a roost at night in winter will achieve a similar result and if you put her there after dark, she cannot see to get down and return to the nest, so she has to stay until morning. If you kick her out of the nest a few times during the day as well, that might be enough to cool her off and discourage her, especially as first time young broodies are often not fully committed to brooding like seasoned broody hens usually are.
Of course some people dunk them in a bucket of cold water each time they find them in the nest but at this time of year that is not recommended! Breaking broodies in winter should be somewhat easier, purely because of the cooler ambient temperature making it more difficult for them to maintain that increased body heat, especially when you deprive them of a comfortable nest to snuggle into.