IT band tightness = is the symptom of something else? Like tight hamstrings and or quads or glutes? I don’t know but the EMS can be used to address any of these large muscle groups initially through an active recovery mode or something that will promote blood flow to loosen the area.
Sounds to me that you need to combine several approaches to get a result.
Massage, epson salt, contrast therapy and follow up with EMS and Travel Roller or a stick or something in this category.
Are both knees bothering you?
I was told a long time ago sprinters often do not address the tband and over time it can lead to issues with your knee. Find someone knowledgeable to show you proper stretches for your hamstrings and quads.