Hi, I tried one once, strange feeling.
Here a good website for sento in Tokyo with information about what kind of bath they have. Just click on the map in the region you want to go in tokyo. After just click on the sento.
If there is this icon
(if the picture does not appear, you can find it here : ICON
It means there is a denkiburo in the sento.
Hope you find one close to where you live.
Here the link : Denki buro map in tokyo