Connect a penis sheath to a gag or a hood with a tube (or you can also buy a "ready to use" solution If you like drinking your piss, you will enjoy it sooner or later. If not - you will have to do your best NOT to enjoy it :-)

Many variants are possible. All you need is a breath-through gag (alone or built-in) and a penis sheath with a tube. For example, a slightly modified enema pants, penis sheath 1 or penis sheath 2 worn under pants with ball sheath and cock ring

In my latest sessions I use Inflatable hood with built-in breath-through inflatable gag and pantyhose with built-in piss condom

For tubings and connectors you can go to a nearest aquarium or garden shop.

Some issues to mention:

• If you are sitting or standing, there is no enough pressure to force the liquid into the right direction, but just enough to pull the sheath off.
• It's very difficult to pee if you have a fully inflated nozzle (or a butt plug) inside and a tight sheath cutting the canals shut outside.

Yeah, and don't forget to drink more before (evil smile :->)