Does anyone know what the Spanish call Soap Shoes or Grind Shoes?
I soap, I am a soaper, I enjoy soaping but I don't know how to say that in Spanish.
mmm in my country (Costa Rica) young people refer to them as "tenis de skate" or "tenis de skater." I'm just going by the images I found of those "soap shoes." Perhaps, what you refer to as "soaping" is just called "patinar (skate)," or "deslizarse (sliding)" which some people (skaters above all) do in public places with their tennis shoes, especially when the floor is wet or something like that (not using roller skates or skateboards, they just slide anywhere!).
I must say I had no idea of what it was until I saw the video... so I have absolutely no clue of how they call them. However I have a suggestion: Many of these movements come from English speaking countries into Spain and people tend to keep the English names. Though pronunciation and sometimes transcription might turn odd, should be fairly easy to use your normal keywords, just add Madrid, for instance and you'll get a breakthrough.
Besides Tenis(shoes) there is the word "zapatillas" for trainers, sneakers ...