Can anyone give me their experience of metal glass scrapers (the kind with a blade and handle)? I see vids of people using these but maybe they are less precious about their sponsored glass, I am concerned about scratching mine. I have the Eheim version but I also notice there is an eye wateringly expensive ADA version. Also, how I am supposed to be using this tool? Lifting up at a narrow angle or pushing down which feels a bit more hazardous. I have used a Dennerle cleanator sponge up to now but thought I would experiment with one of these.