I am on the far end of the fertilizing spectrum: I rarely fertilize in-ground lilies. But I do the potted stuff. In any case, I don't and would not use a sprayer for two reasons:
1 - would prefer not to purposely get foliage wet, and encourage disease and fertilizer spot residue.
2 - A spray doesn't apply much fertilizer, unless you wish to spend a lot of extra time at each plant. And If you use a mulch, most (if not all) of the fertilizer sprayed on will be absorbed by and used up by the mulch organic matter. Eventually it will get to the soil and plants as the mulch breaks down, and that is good, but if you think you are fertilizing for a specific purpose that season, you're fooling yourself.
Usually, I use a watering can with the water breaker detached.