Slice 3 lemons into wedges. Remove any seeds and discard them.
Pour 2 cups water into the microwave-safe bowl. Use a 1-qt. microwave-safe bowl if a the larger bowl does not fit inside your microwave.
Squeeze the juice from the lemon wedges into the bowl of water. Drop each juiced lemon wedge into the water. Lemon zest, which is found in the outer lemon layer known as the rind, contains lemon oil that has a high-concentrate lemon scent.
Place the bowl filled with lemon water and lemon wedges in the middle of the microwave. Turn the microwave on high for about 10 minutes. Turn the microwave off when the lemon water has been boiling for 1 minute.
Let the boiling water sit for 15 minutes inside the microwave. The steam from the lemon water will penetrate any residue on the walls and make it easier to wipe clean.
Remove the bowl of lemon water from the microwave with potholders. The bowl should be cooled significantly after sitting for 15 minutes, but potholders are a safe precaution. Place a potholder on your countertop so the bowl rests on a heat-resistant surface.
Dip a clean, dry rag into the lemon water and wipe down all the walls inside the microwave. Wring out the rag over the sink so dirty water washes down the drain. Dip the rag in the lemon water and wipe down the inside of the microwave a second time.
Leave the microwave door open for about an hour so it completely airs out. The acid from the lemon juice in the water helps clear burnt popcorn residue. The lemon oil in the zest leaves a fresh lemon scent.