Biofilms such as those formed by Candida are almost impregnable fortresses that resist antifungal penetration. Wondro (sulfurated flax oil) that appeared to be quite effective in mopping up the immunosuppressor acetaldehyde emitted by yeast was also used in a more viscous modality called "Black Ointment" for healing of external sores. It was quite effective at preventing infection and promoting the recovery process. I'm not sure what effect it might have on a biofilm colony, per se. The process for making "Black Ointment" is similar to that described for Wondro in the reference except that the amount of sulfur used is increased several-fold.