For best results hold the 'ProScraper' with both hands and pull. The top hand provides pressure over the blade whilst the bottom hand moves the scraper along.
Use an even pressure over the blade without twisting. If the blade edges are occasionally catching the surface then carefully round off the corners of the blade with a file. This should not be necessary if sufficient care is taken in use.
Although the 'ProScraper' is very effective without a vacuum unit connected this would negate it's primary benefit of cleanliness.