Sorry folks..but the only way to make sure the pump in our 5'er is winterized is to put some antifreeze into the FW tank and suck it thru the pump. Pump has no winterizing kit attached to it and is not accessible to put one on it. So I run it for 10 or 15 seconds to make sure all water is out of it and then add just enough antifreeze to the tank so the pump will pick it up, then drain the remaining out. Also there's no gravity hole to fill FW tank so I have to pump it in with another pump. We have a lever to switch from tank fill or city water usage. Been doing this now for the 7 years we've had it. Come spring I sanitize the tank & system good with bleach and have had no antifreeze foam or after taste.
Milo