In a big outdoor ritual into which the offerings are going into a fire on the altar, all things, the incense, the offerings, and liquids, are consumed into the flames to be given to the gods. For most of us who do not have this option, a thought has occurred to me for a more practical indoor practice.
I have a ceramic oil warmer. The principle of this is simple as everyone should know. You put a flame underneath the bowl and whatever liquids you pour within are heated so that they evaporate. Oils are used and these release a sweet smell into the air. Now a libation of oil is not a new thing, so using the essential oils of flowers as offerings rather than the harsher smoky incense can also be very beneficial. And there is no ash to clean up. Plus this libation of oil can be added to your normal libation. For me this means water.
In the past I have either let the water sit in an offering bowl to evaporate or poured it into a potted plant. But why not let water, or even wine (though you would have to clean up the sidements remaining of that..but it is not a chore), evaporate into the air to be received by the gods heated by fire rather than consumed by it? So I pour first the water or wine into the slowly heating ceramic dish. And then I pour in the oil. It is both a sensory explosion and a rather wonderful way to give your offerings. Again very little messy clean up and you can find a wide variety in essential oils that you cannot find in incense.