A few feet of wax paper is completely mess-free (and can even be used to separate a sooty pot from other stuff) and you can use as much or as little as you need each time based on the conditions. A square inch or two under really dry twigs. A dollar-bill-sized piece for bigger twigs. Roll and kink a tube for a longer-lasting one, etc. For the multi-purposers among us, you can use wax paper (or aluminum foil) to catch drips off a snow field or tarp for drinking water. Instant funnel.
Someone posted two weeks ago about filling each compartment of a cardboard egg carton with a tablespoon of wax and cutting out 12 fire starters. I tried it and while not SUL, it made a REALLY effective fire starter - for wetter or bigger wood. I buy big, ugly candles at the thrift store for 25 cents and keep them around as a cheap source of wax.
The SDUL (super-duper ultralight) method is to harvest your own belly-button lint and impregnate it with your own ear wax. NO added pack weight AND you reduce your skin-out weight with each use.