Since my own kids are done showing, I'm not spending as much time watching details. But couple points, unless it just changed the trend to me was to not use surgical blades on show day and clip with fines. If using surgical's then clip a few days before. I too have been told the lube spray doesn't last very long and that oil should be used. I've , also been told that everytime you sharpen a blade you make is shorter and a fine effectively becomes a surgical if sharpened several times.
I've not heard or observed the burning of skin, but we do recommend liberal application of cornhusker's oil after clipping. I like how it keeps the hide.