You not only taught me an essential skill, but you showed me an amazing song on your intro

I drop a long hose in the tank and jerry can, and with a short hose about 2’ long, wrap a rag around it and the long hose and place the rag over the fill hole to seal it. While holding the short hose so it doesn’t fall into the tank, blow air into the short hose and gas will start flowing into the jerry through the long hose.

flash backs to working at an equine hospital and getting a mouthful of bile while siphoning out a horse's stomach... I wish I had something like this haha

You can just fold the hose over to stop the flow. The jiggler siphon's are much better than the old school suck on it method, I did that once to a piece of garden hose & had a big ol' huntsman spider suck into my mouth & dance around until I spat it out.

Neat idea. Since copper is conductive, isn't a spark of concern?

do you have a name or link for the shut off valve?

If he was burping up gas fumes for several days after his siphoning attempt he didn’t just swallow fumes, he took a gulp of gas.