If you treat your machine right you would only have to wipe it down between grows. Ultrasonics are much easier to keep clean. They also put out more humidity and can raise the RH a lot better than the wicking filter style. The wick is just a towel and fan style unit and the filter/wick gets funky. The ultrasonics you have to use RO or distilled water or you get white dust on everything from vaporizing the minerals generally found in tap water.
I think almost all of them are ultrasonics now. Just find one with a mechanical on/off switch and you can let it control itself with an inkbird power strip humidity device. Yeah, extra $$ but lasts and you get easy maintenance.
After that, you can add these in tank bacterial inhibitors. I've seen them on the shelf at target in the humidifier section.
Protec Antimicrobial Cleaning Fish feature a patented antimicrobial, Aquastat that continuously works to hinder the growth of bacteria and mold. Antimicrobial Cleaning Fish is capable of preventing the buildup of slime in the water and humidifier surfaces.
www.honeywellstore.com
But yeah, you should get one. I think. Especially if you already have an RO unit. If not you will end up buying several jugs of distilled water from the store.