Are you sure it's fungus and not just lint build up? If it's just lint build up, try putting an old hose sock (you know, like panty hose but the "sock" version) over the end of the pipe somehow. I used to leave my dryer hose loose in the laundry room to help with heating the house using this "hose" method. You just have to clean your "hose filter" from time to time just like the filter in your dryer. Now, if it IS fungus and you must do this rerouting thing, why not just buy more hose and run it on outside along a wall or something?