I don't know what kind a bators you have, Ki4got has some pics of hers. Maybe see will put them up. I use a towel in water. The towel or sponge acts like a wick and will keep putting water in the air.
Can you see the yellow thing in the corner. I have a sponge and a cut terry clothe towel in there. The towel can be draped across the top so that more area is exposed to evaporate the water. I have it near the fan and heat to help that along. Could you fashion something similar on a small scale?

Can you see the yellow thing in the corner. I have a sponge and a cut terry clothe towel in there. The towel can be draped across the top so that more area is exposed to evaporate the water. I have it near the fan and heat to help that along. Could you fashion something similar on a small scale?