The world would be a better place (or at least more interesting) if we could just swap dicks and vag casually.
Like, yo! Southsamurai, I'm really wanting to see what having a dick feels like, how about we set up a 24 hour swap, my cooter for your pud? Why, absolutely my chum, I shall have your innie professionally cleaned and refueled before return. Please do the same.
Then, while I may suffer some degree of dysphoria for a day, I would perhaps gain a better understanding of things. And my hypothetical penis borrower friend would perhaps gain a better understanding of why you pay a great deal of attention to your zipper during certain times. I suspect that simply informing them and thereby avoiding a painful return of the ol' tallywhacker would fall in deaf ears, so they would likely have to learn first hand.
Of course, for those seeking a long term or permanent exchange, you could have speed genitaling, where a bunch of prospective swappers meet while bottomless to find a nice match. "Oh, dear friend! I do declare, I suspect our parts would make for a glorious exchange! Such a lovely shade of flesh tone!" "Why, indeed! They do match rather well, let us hie to the grafting office and arrange an exchange!"
And such fun would be had by all