TBPH, it depends on the fabric. Plain flat ( non shiny) ballet leos are completely different from sparkly/shiny leos or other leo. Those could potentially go into a regular load but we never did that
When we did dance, they washed their leos on delicate in the washer with woolite or another delicate detergent with tights in a lingerie bag and hung to dry. Or hand washed in a bucket and hung to dry.
Now we only have a kid who does gymnastics with is another entirely different ball game (cuz almost every leo is sparkly with some sort of decor
).