Originally Posted by Mopar1973Man
...I used my homemade blow out plug and life was easy...
Wow! That that's a bit of engineering there; an "M" style plug, to a bushing, to and adapter with GHT (Garden Hose Thread). However, I'd probably go your route rather than pay $14.95 (plus shipping) for the "professional", patented, one piece model shown below.
Here's the link to their site if anyone's interested in buying one.
Winterize Manufacturing - Quick Connect RV Blow Out Plug
On the original topic, after draining the tank, I stuff the end of a rag into the opening instead replacing the plug to keep critters and debris out yet allow a little air to ventilate into the tank.