If you are rightly concerned about chucking expensive absinthe down the drain then consider straining into a shot glass and serve on the side. The roughly...
My favorite drink. I make mine with bourbon or rye & Peychaud Bitters 3-4 dashes to make it on the spicier side. I like mine sweet so I use more simple syrup than most will. And I definitely guzzle that extra absinthe, no way would I waste it. For my customers that do not prefer the flavor of absinthe, I use a spray aspirator and spray 2-3 spritzes over the top so they get the scent with very little flavor. But I coat mine! I use fennel from my garden to garnish for added scent.
This is a beautiful sazerac, wonderfully aromatic, even with a bottle of Peychaud bitters that was likely past its best. Still need to practise the throwing technique a bit more though!